Artificial reality systems with hand gesture-contained content window

ABSTRACT

An artificial reality system is described that renders, presents, and controls user interface elements within an artificial reality environment, and performs actions in response to one or more detected gestures of the user. The artificial reality system includes an image capture device configured to capture image data representative of a physical environment, a head-mounted display (HMD) configured to output artificial reality content, a gesture detector configured to identify, from the image data, a gesture comprising a configuration of a hand that is substantially stationary for at least a threshold period of time and positioned such that a thumb of the hand and at least one other finger form approximately a circle or approximately a circular segment, a user interface (UI) engine to generate a UI element in response to the identified gesture, and a rendering engine to render the UI element as an overlay to the artificial reality content.

TECHNICAL FIELD

This disclosure generally relates to artificial reality systems, such asvirtual reality, mixed reality, augmented reality, and/or othercomputer-mediated reality systems, and more particularly, to userinterfaces of artificial reality systems.

BACKGROUND

Artificial reality systems are becoming increasingly ubiquitous withapplications in many fields such as computer gaming, health and safety,industrial, and education. As a few examples, artificial reality systemsare being incorporated into mobile devices, gaming consoles, personalcomputers, movie theaters, and theme parks. In general, artificialreality is a form of reality that has been adjusted in some mannerbefore presentation to a user, which may include, e.g., a virtualreality (VR), an augmented reality (AR), a mixed reality (MR), a hybridreality, or some combination and/or derivatives thereof.

Typical artificial reality systems include one or more devices forrendering and displaying content to users. As one example, an artificialreality system may incorporate a head-mounted display (HMD) worn by auser and configured to output artificial reality content to the user.The artificial reality content may include completely-generated contentor generated content combined with captured content (e.g., real-worldvideo and/or images). During operation, the user typically interactswith the artificial reality system to select content, launchapplications or otherwise configure the system.

SUMMARY

In general, this disclosure describes artificial reality systems and,more specifically, system configurations and techniques for presentingand controlling user interface (UI) elements within an artificialreality environment. Some examples of the techniques and systemconfigurations of this disclosure are directed to invoking UI elementsin response to detecting or identifying particular gestures performed bya user. The invocation of UI elements is also referred to throughoutthis disclosure as “triggering” the UI elements or “gating” the UIelements. Examples of such UI elements include, but are not limited to,menus of user-selectable options. Aspects of this disclosure are alsodirected to modifying a presently-rendered UI element in response todetecting certain gestures, such as by changing an orientation or datagranularity-level of the UI element in response to these gestures.

For example, artificial reality systems are described that generate andrender graphical UI elements for display to a user in response todetection of one or more pre-defined gestures performed by the user, asdefined in a gesture library accessible to the artificial realitysystems. Examples of such gestures include particular motions,movements, static configurations, moving configurations, positions,relative positions, and/or orientations of the user's hands, fingers,thumbs or arms, or a combination of pre-defined gestures. In someexamples, the artificial reality system may further trigger generationand rendering of the graphical user interface elements in response todetection of particular gestures in combination with other conditions,such as the position and orientation of the particular gestures in aphysical environment relative to a current field of view of the user,which may be determined by real-time gaze tracking of the user, orrelative to a pose of an HMD worn by the user.

In some examples, the artificial reality system may generate and presentgraphical UI (GUI) elements as overlay elements with respect to theartificial reality content currently being rendered within the displayof the artificial reality system. The UI elements may, for example,include, be, or be part of interactive GUI elements, such as a menu orsub-menu with which the user interacts to operate the artificial realitysystem. The UI elements may, in some instances, include individual GUIelements, such as elements that are selectable and/or manipulatable by auser. In various examples, such individual GUI elements include one ormore of toggle (or togglable) elements, drop-down elements, menuselection elements (e.g., checkbox-based menus), two-dimensional orthree-dimensional shapes, graphical input keys or keyboards, contentdisplay windows, and the like.

In one example, an artificial reality system includes an image capturedevice configured to capture image data representative of a physicalenvironment, a head-mounted display (HMD) configured to outputartificial reality content, a gesture detector configured to identify,from the image data, a gesture comprising a configuration of a hand thatis substantially stationary for at least a threshold period of time andpositioned such that a thumb of the hand and at least one other fingerof the hand form approximately a circle or approximately a circularsegment, a user interface (UI) engine configured to generate a UIelement in response to the identified gesture, and a rendering engineconfigured to render the UI element as an overlay to the artificialreality content.

The details of one or more examples of the techniques of this disclosureare set forth in the accompanying drawings and the description below.Other features, objects, and advantages of the techniques will beapparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is an illustration depicting an example artificial realitysystem that presents and controls user interface elements within anartificial reality environment in accordance with the techniques of thedisclosure.

FIG. 1B is an illustration depicting another example artificial realitysystem in accordance with the techniques of the disclosure.

FIG. 2 is an illustration depicting an example HMD that operates inaccordance with the techniques of the disclosure.

FIG. 3 is a block diagram showing example implementations of a consoleand an HMD of the artificial reality systems of FIGS. 1A, 1B.

FIG. 4 is a block diagram depicting an example in which gesturedetection and user interface generation is performed by the HMD of theartificial reality systems of FIGS. 1A, 1B in accordance with thetechniques of the disclosure.

FIG. 5 is a flowchart illustrating a process that artificial realitysystems of this disclosure may perform in accordance with thegesture-driven UI element gating techniques of this disclosure.

FIGS. 6A-6D illustrate corner-based gating configurations of a hand andUI elements that artificial reality systems of this disclosure mayinvoke in response to the identification of the corner-based gatingconfigurations of hand.

FIGS. 7A and 7B illustrate rounded-boundary configurations of a handthat artificial reality systems of this disclosure may detect as stimulifor gating certain UI elements within a virtual environment representedby artificial reality content.

FIGS. 8A and 8B illustrate configurations of an arm that artificialreality systems of this disclosure may detect as stimuli for gatingcertain UI elements within a virtual environment represented byartificial reality content.

FIGS. 9A-9C illustrate various configurations of a hand that form agrip-and-throw gesture in response to which artificial reality systemsof this disclosure may gate UI elements, in accordance with some aspectsof this disclosure.

FIGS. 10A and 10B illustrate various configurations of a hand and anopposite arm that gesture detectors of this disclosure may use to detectgestures that generally correspond to gripping (or “holding” or“grabbing”) gestures originating from predefined areas of the oppositearm.

FIG. 11 illustrates a grip-and-pull gesture of a hand originating froman opposite wrist and UI elements that artificial reality systems ofthis disclosure may invoke in response to the identification of thegrip-and-pull gesture.

Like reference characters refer to like elements throughout the figuresand description.

DETAILED DESCRIPTION

FIG. 1A is an illustration depicting an example artificial realitysystem 10 that presents and controls user interface elements within anartificial reality environment in accordance with the techniques of thedisclosure. In some example implementations, artificial reality system10 generates and renders graphical user interface elements to a user 110in response to one or more gestures performed by user 110 and detectedby artificial reality system 10 and/or component(s) thereof. That is, asdescribed herein, artificial reality system 10 presents one or moregraphical user interface elements 124, 126 in response to detecting oneor more particular gestures performed by user 110, such as particularmotions, configurations, locations, and/or orientations of the user'shands, fingers, thumbs, arms, etc.

In some examples, artificial reality system 10 may detect a predefinedgesture based on additional conditions being satisfied, such as theposition and orientation of portions of arm 134 (e.g., a wrist) and/orhand 132 (or digits thereof) in a physical environment in relation to acurrent field of view 130 of user 110, as may be determined by real-timegaze tracking of the user, or other conditions. In other examples,artificial reality system 10 presents and controls user interfaceelements specifically designed for user interaction and manipulationwithin an artificial reality environment, such as menu selectionelements (e.g., a menu that includes one or more user-selectableoptions), specialized toggle elements, drop-down elements, graphicalinput keys or keyboards, content display windows, and the like.

In the example of FIG. 1A, artificial reality system 10 includes headmounted device (HMD) 112, console 106 and, in some examples, one or moreexternal sensors 90. As shown, HMD 112 is typically worn by user 110 andincludes an electronic display and optical assembly for presentingartificial reality content 122 to user 110. In addition, HMD 112includes one or more sensors (e.g., accelerometers) for tracking motionof HMD 112. HMD 112 may include one or more image capture devices 138,e.g., cameras, line scanners, and the like. Image capture devices 138may be configured for capturing image data of the surrounding physicalenvironment. In this example, console 106 is shown as a single computingdevice, such as a gaming console, workstation, a desktop computer, or alaptop.

In other examples, console 106 may be distributed across a plurality ofcomputing devices, such as a distributed computing network, a datacenter, or a cloud computing system. Console 106, HMD 112, and sensors90 may, as shown in this example, be communicatively coupled via network104, which may be a wired or wireless network, such as a Wi-Fi® or 5G®based network, an Ethernet network, a mesh network or a short-rangewireless (e.g., Bluetooth®) communication medium. Although HMD 112 isshown in this example as in communication with, e.g., tethered to or inwireless communication with, console 106, in some implementations HMD112 operates as a stand-alone, mobile artificial reality system.

In general, artificial reality system 10 uses information captured froma real-world, three-dimensional (3D) physical environment to renderartificial reality content 122 for display to user 110. In the exampleof FIG. 1A, user 110 views the artificial reality content 122constructed and rendered by an artificial reality application executingon console 106 and/or HMD 112. As one example, artificial realitycontent 122 may be a consumer gaming application in which user 110 isrendered as avatar 120 with one or more virtual objects 128A, 128B. Insome examples, artificial reality content 122 may comprise a mixture ofreal-world imagery and virtual objects, e.g., mixed reality and/oraugmented reality. In other examples, artificial reality content 122 maybe, e.g., a video conferencing application, a navigation application, aneducational application, training or simulation applications, or othertypes of applications that implement artificial reality.

During operation, the artificial reality application constructsartificial reality content 122 for display to user 110 by tracking andcomputing pose information for a frame of reference, typically a viewingperspective of HMD 112. Using HMD 112 as a frame of reference, and basedon a current field of view 130 as determined by a current estimated poseof HMD 112, the artificial reality application renders 3D artificialreality content which, in some examples, may be overlaid, at least inpart, upon the real-world, 3D physical environment of user 110. Duringthis process, the artificial reality application uses sensed datareceived from HMD 112, such as movement information and user commands,and, in some examples, data from any external sensors 90, such asexternal cameras 102A and/or 102B, to capture 3D information within thereal world, physical environment, such as motion by user 110 and/orfeature tracking information with respect to user 110. Based on thesensed data, the artificial reality application determines a currentpose for the frame of reference of HMD 112 and, in accordance with thecurrent pose, renders the artificial reality content 122.

Moreover, in accordance with the techniques of this disclosure, based onthe sensed data, the artificial reality application detects gesturesperformed by user 110 and, in response to detecting one or moreparticular gestures, generates one or more user interface elements,e.g., UI menu 124 and UI element 126, which may be overlaid onunderlying artificial reality content 122 being presented to user 110.In this respect, user interface elements 124, 126 may be viewed as partof the artificial reality content 122 being presented to user 110 in theartificial reality environment. In this way, artificial reality system10 dynamically presents one or more graphical user interface elements124, 126 in response to detecting one or more particular gestures byuser 110, such as particular motions, configurations, positions, and/ororientations of the user's hands, fingers, thumbs or arms. Exampleconfigurations of a user's hand may include a fist, a partial first withone or more digits extended, an open hand with all digits extended, agripping configuration in which two or more fingers encircle a virtualobject, the relative and/or absolute positions and orientations of oneor more of the individual digits of hand 132, the shape of the palm ofthe hand (e.g., substantially flat, cupped, etc.), and so on.

The user interface elements may, for example, include, be, or be part ofa graphical user interface, such as a menu or sub-menu with which user110 interacts to operate the artificial reality system, or individualuser interface elements selectable and manipulatable by user 110, suchas toggle elements, drop-down elements, menu selection elements,two-dimensional or three-dimensional shapes, graphical input keys orkeyboards, content display windows and the like. While depicted as atwo-dimensional element, for example, UI element 126 may be atwo-dimensional or three-dimensional shape that is manipulatable by user110 by performing gestures to translate, scale, and/or rotate the shapewithin the virtual environment represented by artificial reality content122.

Moreover, as described herein, in some examples, artificial realitysystem 10 may trigger generation and rendering of graphical userinterface elements 124, 126 in response to other conditions, such as acurrent state of one or more applications being executed by the system,or the position and orientation of the particular detected gestures in aphysical environment in relation to a current field of view 130 of user110, as may be determined by real-time gaze tracking of the user, orother conditions. More specifically, as further described herein, imagecapture devices 138 of HMD 112 capture image data representative ofobjects in the real world, physical environment that are within a fieldof view 130 of image capture devices 138. Field of view 130 typicallycorresponds with the viewing perspective of HMD 112.

In some examples, such as the illustrated example of FIG. 1A, theartificial reality application renders the portions of hand 132 of user110 that are within field of view 130 as a virtual hand 136 withinartificial reality content 122. In other examples, the artificialreality application may present a real-world image of hand 132 and/orarm 134 of user 110 within artificial reality content 122 comprisingmixed reality, augmented reality, and/or any other combination ofinformation directly reproducing a physical environment withcomputer-mediated content. In either example, user 110 is able to viewthe portions of his/her hand 132 and/or arm 134 that are within field ofview 130 as objects within the virtual environment represented byartificial reality content 122. In other examples, the artificialreality application may not render hand 132 or arm 134 of user 110 atall within artificial reality content 122.

During operation, artificial reality system 10 performs objectrecognition within image data captured by image capture devices 138 ofHMD 112 (and/or by external cameras 102) to identify hand 132, includingoptionally identifying individual fingers or the thumb, and/or all orportions of arm 134 of user 110. Further, artificial reality system 10tracks the position, orientation, and configuration of hand 132(optionally including particular digits of the hand) and/or portions ofarm 134 over a sliding window of time. The artificial realityapplication analyzes any tracked motions, configurations, positions,and/or orientations of hand 132 and/or portions of arm 134 to identifyone or more gestures performed by particular objects, e.g., hand 132(including but not limited to one or more particular digits of hand 132)and/or portions of arm 134 (or specific portions thereof, such as awrist) of user 110.

To detect the gesture(s), the artificial reality application may comparethe motions, configurations, positions and/or orientations of hand 132and/or portions of arm 134 to gesture definitions stored in a gesturelibrary of artificial reality system 10, where each gesture in thegesture library may be each mapped to one or more actions. In someexamples, detecting movement may include tracking positions of one ormore of the digits (individual fingers and thumb) of hand 132, includingwhether any of a defined combination of the digits (such as an indexfinger and thumb) are brought together to touch or approximately touchin the physical environment, or to bookend or encircle a user interfaceelement (e.g., an assistant element or a display element) presented aspart of artificial reality content 122. In other examples, detectingmovement may include tracking an orientation of hand 132 (e.g., fingerspointing toward HMD 112 or away from HMD 112) and/or an orientation ofarm 134 (i.e., the normal of the arm facing toward HMD 112) relative tothe current pose of HMD 112. The position and orientation of therespective portion or entirety of hand 132 or arm 134 thereof mayalternatively be referred to as the pose of hand 132 or arm 134, or aconfiguration of hand 132 or arm 134.

Moreover, the artificial reality application may analyze configurations,motions, positions, and/or orientations of hand 132 and/or arm 134 toidentify a gesture that includes hand 132 and/or arm 134 being held inone or more specific configuration, movement, positions, and/ororientations for at least a threshold period of time. As examples, oneor more particular positions at which hand 132 and/or arm 134 are beingheld substantially stationary within field of view 130 for at least aconfigurable period of time may be used by artificial reality system 10as an indication that user 110 is attempting to perform a gestureintended to trigger a desired response by the artificial realityapplication, such as triggering display of a particular type of userinterface element 124, 126, such as a menu.

As another example, one or more particular configurations of the digits(fingers or thumb) and/or palms of hand 132 and/or arm 134 beingmaintained within field of view 130 for at least a configurable periodof time may be used by artificial reality system 10 as an indicationthat user 110 is attempting to perform a gesture. For instance,artificial reality system 10 may use the detected image data as anindication that user 110 is attempting to perform a predefined gesturestored to a gesture library accessible to artificial reality system 10.Although only a right hand and a right arm of user 110 are illustratedin FIG. 1A as hand 132 and right arm 134, it will be appreciated that,in various examples, artificial reality system 10 may identify a lefthand and/or arm of user 110 or both right and left hands and/or arms ofuser 110 for the gesture detection techniques of this disclosure. Inthis way, artificial reality system 10 may detect single-handed gesturesperformed by either hand, double-handed gestures, or arm-based gestureswithin the physical environment, and generate associated user interfaceelements in response to the detected gestures.

In accordance with some examples of the system configurations andtechniques of this disclosure, the artificial reality applicationrunning on artificial reality system 10 determines whether an identifiedgesture corresponds to a predefined gesture defined by one of aplurality of entries in a gesture library. The gesture library may bestored locally at or otherwise accessible to console 106 and/or HMD 112.As described in more detail below, each of the entries in the gesturelibrary may define a different gesture as a specific motion,configuration, position, and/or orientation of a user's hand, digit(finger or thumb) and/or arm over time, or a combination of suchproperties. In addition, each of the defined gestures may be associatedwith a desired response in the form of one or more actions to beperformed by the artificial reality application.

As one example, one or more of the predefined gestures in the gesturelibrary may trigger the generation, transformation, and/or configurationof one or more user interface elements, e.g., UI menu 124, to berendered and overlaid on artificial reality content 122, where thegesture may define a location and/or orientation of UI menu 124 inartificial reality content 122. As another example, one or more of thedefined gestures may indicate an interaction by user 110 with aparticular user interface element, e.g., selection of UI element 126 ofUI menu 124, to trigger a change to the presented user interface,presentation of a sub-menu of the presented user interface, or the like.

Again, some examples of the techniques and system configurations of thisdisclosure are directed to invoking UI elements in response to detectingor identifying particular gestures performed by a user. The invocationof UI elements is also referred to throughout this disclosure as“triggering” the UI elements or “gating” the UI elements. Examples ofsuch UI elements include, but are not limited to, menus ofuser-selectable options. Aspects of this disclosure are also directed tomodifying a presently-rendered UI element in response to detectingcertain gestures, such as by changing an orientation or datagranularity-level of the UI element in response to these gestures.Examples of gestures that artificial reality system 10 may use forgating purposes include the positioning of hand 132 in certainconfigurations for a threshold period of time, or certain configurationsand movements of hand 132 at locations that correspond to virtuallocations of already-displayed UI elements. As used herein, the term“gating” refers to the generation and rendering of certain UI elementsthat were not displayed in the virtual environment until the gatingevent occurs.

According to some of the techniques described herein, the artificialreality application running on artificial reality system 10 performs UIelement gating in response to detecting gestures in which hand 132 isconfigured such that two of the digits form approximately a right angle.For example, artificial reality system 10 detects the gating gesture ifan index finger and a thumb of hand 132 form approximately a rightangle. In some examples, artificial reality system 10 adds a temporalcomponent to the criteria for the gating gesture to be recognized. Thatis, artificial reality system 10 may identify the gesture if theconfiguration of hand 132 is substantially stationary for at least athreshold period of time, and during the period of time during whichhand 132 is stationary, and hand 132 is positioned such that the indexfinger and the thumb of hand 132 form approximately a right angle. Itwill be appreciated that, while the position of hand 132 is describedherein as forming an “angle” as represented by a turn between twostraight lines, artificial reality system 10 adjusts the angledetermination of this disclosure to accommodate human anatomicalidiosyncrasies, such as the curvature of the webbing between the thumband index finger, any natural bends caused by inter-phalange joints ofthe fingers of hand 132, etc.

In some examples, artificial reality system 10 identifies differentgating gestures based on the orientation of hand 132 when the indexfinger and thumb are positioned approximately at the right angle. Forexample, artificial reality system 10 may identify one gating gesture ifa back surface of hand 132 is facing HMD 112, and may identify adifferent gating gesture if a palm of hand 132 is facing HMD 112. Thatis, artificial reality system 10 may identify the gating gesture basedon certain attributes of hand 132 while hand 132 (or a particularportion thereof) is within the field of view (FoV) of user 110 whileuser 110 is wearing HMD 112. As another example, artificial realitysystem 10 may identify one gating gesture if the thumb of hand 132 isfacing upwards in the FoV of HMD 112, and may identify a differentgating gesture if the index finger of hand 132 is facing upwards in theFoV of HMD 112. In some examples, artificial reality system 10 mayrecognize the particular gestures based on a combination of the variousorientation attributes of hand 132 described above.

According to some techniques of this disclosure, artificial realitysystem 10 detects a gating gesture if hand 132 is positionedsubstantially stationary for at least the threshold period of time, andthe digits of hand 132 are positioned such that such that the thumb andat least one other finger of hand 132 form approximately a circle orapproximately a circular segment. In some examples, artificial realitysystem 10 may detect the gesture if the view of hand 132 facing the FoVof HMD 112 is a sideways orientation, and represents the side of hand132 on which the thumb is located. For instance, the normal drawn fromHMD 112 to hand 132 may intersect with the inside area of the circle orcircular segment formed by the thumb and the other finger(s) of hand132. It will be appreciated that, while the configuration of hand 132 isdescribed herein as approximately forming the geometric shapes of a“circle” or a “circular segment”, artificial reality system 10 adjuststhe angle determination of this disclosure to accommodate humananatomical idiosyncrasies, such as the sharper bends caused byinter-phalange joints of the fingers of hand 132, folds in the webbingbetween the thumb and index finger, etc. In these examples, artificialreality system 10 may gate a UI element at a virtual locationcorresponding to the space between the virtual representations of theindex finger and thumb.

According to some techniques of this disclosure, artificial realitysystem 10 detects a gating gesture if a portion of arm 134 is positionedsubstantially stationary for at least the threshold period of time, andis in the FoV of HMD 112 for at least the threshold period of time. Forexample, artificial reality system 10 may detect the gesture if theconfiguration of arm 134 is such that a wrist is substantiallystationary for at least a threshold period of time, and the wrist ispositioned such that a normal from the wrist faces the FoV of HMD 112.In some examples, artificial reality system 10 may detect the gesture ifthe view of arm 134 facing external cameras 102 and/or image capturedevices 138 of HMD 112 is a sideways orientation, and represents theinner side of the wrist, i.e. the side on which the thumb of hand 132 islocated. For instance, the normal drawn from HMD 112 to hand 132 mayintersect with the inside surface of the wrist of arm 134. In theseexamples, artificial reality system 10 may gate a UI element at avirtual location corresponding to a representation of the oppositewrist.

According to some techniques of this disclosure, artificial realitysystem 10 adds a display element to artificial reality content 122output by HMD 112 for user 110 to view. The display element may, in somecases, be referred to as an “assistant” with respect to the gatingtechniques described herein. According to these examples, artificialreality system 10 may detect certain predefined gestures performed atlocations generally corresponding to the location of the display elementto gate UI elements within artificial reality content 122.

In some implementations, a UI engine of artificial reality system 10 maygenerate an assistant element to simulate a drone, in that the assistantelement hovers over or alongside a virtual representation (e.g. anavatar) of user 110, e.g., alongside virtual hand 136, in the virtualenvironment represented by artificial reality content 122. In theseimplementations, artificial reality system 10 may detect the gesturebased on a grip-and-throw combination performed by hand 132 with respectto the assistant element included in artificial reality content 122.

For example, artificial reality system 10 may detect a gating gesture ifartificial reality system 10 identifies a combination of (1) a grippingmotion of two or more digits of hand 132 to form a grippingconfiguration at a location that corresponds to the assistant elementwithin the virtual environment represented by artificial reality content122, and (2) a throwing motion of hand 132 with respect to the assistantelement, where the throwing motion occurs subsequent to the grippingmotion. For instance, artificial reality system 10 may detect thethrowing motion by identifying a combination of a release of thegripping configuration of hand 132 and a particular movement of hand 132and/or arm 134. The particular movement that accompanies, follows, orpartially overlaps with the release of the gripping configuration mayinclude one or more of a flexion of hand 132 or the wrist of arm 134, anoutward flicking motion of at least one of the digits of hand 132, orthe like. In these examples, artificial reality system 10 may gate a UIelement at a virtual location corresponding to where the assistantelement was virtually thrown.

In some implementations, the UI engine of artificial reality system 10may generate the display element to simulate a wearable orpartially-adhesive entity. For instance, the UI engine of artificialreality system 10 may cause a rendering engine of artificial realitysystem 10 to output the display element at a location corresponding to arepresentation of an opposite arm of user 110 (i.e., the arm other arm134). In one example, the UI engine and the rendering engine ofartificial reality system 10 render the display element to appearsuperimposed on and attached to the opposite arm of user 110. In somesuch implementations, artificial reality system 10 may detect thegesture based on a grip-and-move combination, a grip-and-releasecombination, a grip-move-release combination, or simply a grip performedby hand 132 with respect to the assistant element that appearssuperimposed on and attached to the opposite arm of user 110.

For example, artificial reality system 10 may detect the gesture byidentifying a gripping motion of hand 132 with respect to the displayelement that is placed on the opposite arm of user 110 in the virtualenvironment represented by artificial reality content 122. In responseto the identification of the gesture, artificial reality system 10 mayupdate the display element to appear detached and separate from theopposite arm of user 110. Artificial reality system 10 may also gate aUI element in response to the identification of the predefined gesture.For example, the UI engine and rendering engine of artificial realitysystem 10 may invoke a menu of user-selectable options within thevirtual environment represented by artificial reality system 122. Insome instances, artificial reality system 10 may position the UI elementnext to or otherwise in the general vicinity of the display element,while the display element still appears detached and separate from theopposite arm of user 110.

In some implementations, artificial reality system 10 may gate a UIelement (e.g., a menu of user-selectable options), in response toidentifying movements such as a grip-and-pull combination or apinch-and-pull combination that originates at a predefined area of theother arm of user 110, such as at the wrist of the other arm. Accordingto some of these implementations, the UI engine and the rendering engineof artificial reality system 10 may output a UI element as an overlay toa representation of the wrist of the other arm in artificial realitycontent 122.

In these implementations, the UI engine and the rendering engine ofartificial reality system 10 may gate the UI menu by modifying the UIelement, in response to identifying a grip-and-pull combination motionof hand 132 with respect to the UI element virtually overlaid on thewrist. For example, artificial reality system 10 may identify a grippingmotion of two or more digits of hand 132 to form a grippingconfiguration, and a subsequent pulling motion of the same two or moredigits away from the wrist of the other hand, while the same two or moredigits are in the gripping configuration. That is, artificial realitysystem 10 may detect the gripping configuration at the location, withinthe virtual environment represented by artificial reality content 122,of the UI element overlaid on the wrist. In this way, these particularaspects of this disclosure described above simulate a drawer or filingcabinet in terms of invoking UI elements.

Accordingly, the techniques and system configurations of this disclosureprovide specific technical improvements to the computer-related field ofrendering and displaying content by an artificial reality system. Forexample, artificial reality systems as described herein may provide ahigh-quality artificial reality experience to a user, such as user 110,of the artificial reality application by generating and rendering userinterface elements overlaid on the artificial reality content based ondetection of intuitive, yet distinctive, gestures performed by the user.

Further, systems as described herein may be configured to detect certaingestures based on hand and arm movements that are defined to avoidtracking occlusion. Tracking occlusion may occur when one hand of theuser at least partially overlaps the other hand, making it difficult toaccurately track the individual digits (fingers and thumb) on each hand,as well as the position and orientation of each hand. Systems asdescribed herein, therefore, may be configured to primarily detectsingle-handed or single arm-based gestures. The use of single-handed orsingle arm-based gestures may further provide enhanced accessibility tousers having large- and fine-motor skill limitations. Furthermore,systems as described herein may be configured to detect double-handed ordouble arm-based gestures in which the hands of the user do not interactor overlap with each other.

In addition, systems as described herein may be configured to detectgestures that provide self-haptic feedback to the user. For example, athumb and one or more fingers on each hand of the user may touch orapproximately touch in the physical world as part of a pre-definedgesture indicating an interaction with a particular user interfaceelement in the artificial reality content. The touch between the thumband one or more fingers of the user's hand may provide the user with asimulation of the sensation felt by the user when interacting directlywith a physical user input object, such as a button on a physicalkeyboard or other physical input device.

In various examples, to perform the gesture detection/identificationaspects of the techniques described above, artificial reality system 10may match detected image data to predefined gestures stored to a gesturelibrary accessible to artificial reality system 10. Artificial realitysystem 10 may, in various implementations, populate the entries of thegesture library with predefined gestures that do not necessarily callfor an interaction with virtual controller or a physical device.Artificial reality system 10 may also include a UI engine configured togenerate various elements described herein, whether in response toparticular stimuli or not. Artificial reality system 10 may also includea rendering engine configured to render artificial reality content 122.

In this way, artificial reality system may be configured according tovarious aspects of this disclosure to enable user 110 to invoke or gateparticular UI elements in the artificial reality-enhanced physicalenvironment by performing particular gestures. By using predefinedgestures that are easy to perform and do not require user 110 to hold aphysical device, artificial reality system 10 of this disclosureleverages the ease of performing these gestures during the course ofregular artificial reality operation to use these particular gestures ofUI element gating within the virtual environment represented byartificial reality content 122.

FIG. 1B is an illustration depicting another example artificial realitysystem 20 in accordance with the techniques of the disclosure. Similarto artificial reality system 10 of FIG. 1A, in some examples, artificialreality system 20 of FIG. 1B may present and control user interfaceelements specifically designed for user interaction and manipulationwithin an artificial reality environment. Artificial reality system 20may also, in various examples, generate and render certain graphicaluser interface elements to a user in response detection of to one ormore particular gestures of the user.

In the example of FIG. 1B, artificial reality system 20 includesexternal cameras 102A and 102B (collectively, “external cameras 102”),HMDs 112A-112C (collectively, “HMDs 112”), controllers 114A and 114B(collectively, “controllers 114”), console 106, and sensors 90. As shownin FIG. 1B, artificial reality system 20 represents a multi-userenvironment in which an artificial reality application executing onconsole 106 and/or HMDs 112 presents artificial reality content to eachof users 110A-110C (collectively, “users 110”) based on a currentviewing perspective of a corresponding frame of reference for therespective user 110. That is, in this example, the artificial realityapplication constructs artificial content by tracking and computing poseinformation for a frame of reference for each of HMDs 112. Artificialreality system 20 uses data received from cameras 102, HMDs 112, andcontrollers 114 to capture 3D information within the real-worldenvironment, such as motion by users 110 and/or tracking informationwith respect to users 110 and objects 108, for use in computing updatedpose information for a corresponding frame of reference of HMDs 112. Asone example, the artificial reality application may render, based on acurrent viewing perspective determined for HMD 112C, artificial realitycontent 122 having virtual objects 128A-128C (collectively, “virtualobjects 128”) as spatially overlaid upon real world objects 108A-108C(collectively, “real world objects 108”). Further, from the perspectiveof HMD 112C, artificial reality system 20 renders avatars 120A, 120Bbased upon the estimated positions for users 110A, 110B, respectively.

Each of HMDs 112 concurrently operates within artificial reality system20. In the example of FIG. 1B, each of users 110 may be a “player” or“participant” in the artificial reality application, and any of users110 may be a “spectator” or “observer” in the artificial realityapplication. HMD 112C may each operate substantially similar to HMD 112of FIG. 1A by tracking hand 132 and/or arm 124 of user 110C, andrendering the portions of hand 132 that are within field of view 130 asvirtual hand 136 within artificial reality content 122. HMD 112B mayreceive user inputs from controllers 114A held by user 110B. HMD 112Amay also operate substantially similar to HMD 112 of FIG. 1A and receiveuser inputs by tracking movements of hands 132A, 132B of user 110A. HMD112B may receive user inputs from controllers 114 held by user 110B.Controllers 114 may be in communication with HMD 112B using near-fieldcommunication of short-range wireless communication such as Bluetooth®,using wired communication links, or using another type of communicationlinks.

In a manner similar to the examples discussed above with respect to FIG.1A, console 106 and/or HMD 112C of artificial reality system 20generates and renders user interface elements 124, 126, which may beoverlaid upon the artificial reality content 122 displayed to user 110C.Moreover, console 106 and/or HMD 112C may trigger the generation anddynamic display of the user interface elements 124, 126 based ondetection, via pose tracking, of intuitive, yet distinctive, gesturesperformed by user 110C. For example, artificial reality system 20 maydynamically present one or more graphical user interface elements 124,126 in response to detecting one or more particular gestures by user110C, such as particular motions, configurations, positions, and/ororientations of the user's hands, fingers, thumbs, or arms. As shown inFIG. 1B, in addition to image data captured via camera 138 of HMD 112C,input data from external cameras 102 may be used to track and detectparticular motions, configurations, positions, and/or orientations ofhands and arms of users 110, such as hand 132 of user 110C, includingmovements of individual and/or combinations of digits (fingers, thumb)of hand 132. External cameras 102 and/or image capture devices 138 ofHMD 112 are referred to collectively as the “image capture device(s)” ofartificial reality system 20, as it will be appreciated that theartificial reality application running on artificial reality system 20may capture image data of the physical environment and of the variousgestures described herein using any one or more of these image capturedevice(s).

In accordance with techniques described in this disclosure, artificialreality system 20 may detect one or more particular configurations ofthe digits (fingers or thumb) and/or palms of hand 132 and/or arm 134 ofuser 110C being maintained within field of view 130 for at least aconfigurable period of time, and interpret the held configuration as anindication that the respective user 110C is attempting to perform agesture. For instance, artificial reality system 20 may use the detectedimage data as an indication that user 110C is attempting to perform apredefined gesture stored to a gesture library accessible to artificialreality system 20. Although only a right hand and a right arm of user110C are illustrated in FIG. 1B as hand 132 and right arm 134, it willbe appreciated that, in various examples, artificial reality system 20may identify a left hand and/or arm of the respective user 110C or bothright and left hands and/or arms of the respective user 110C for thegesture detection techniques of this disclosure.

In this way, artificial reality system 20 may detect single-handedgestures performed by either hand, double-handed gestures, or arm-basedgestures within the physical environment, and generate associated userinterface elements in response to the detected gestures. By leveraginghand-only gestures, hand-and-wrist-only gestures, single-handedgestures, and/or by gestures in which not all of the digits of hand 132are required for gesture detection, artificial reality system 20improves accessibility to users 110, to accommodate disabilities,anatomical idiosyncrasies, injuries, temporary illnesses, etc.

The artificial reality application running on artificial reality system20 may gate (or “trigger”) the generation, rendering, transformation,and/or configuration of one or more user interface elements, e.g., UImenu 124, to be rendered and overlaid on artificial reality content 122,where the gesture may define a location and/or orientation of UI menu124 in artificial reality content 122. As described above in furtherdetail with respect to FIG. 1A, in accordance with various examples ofthe system configurations and techniques of this disclosure, theartificial reality application running on artificial reality system 20may gate the UI element(s) in response to detecting a single-handedgesture performed by hand 132 in which two digits form approximately aright angle (e.g. to form approximately an ‘L’ shape or a mirror imageof an approximate ‘L’ shape). According to other techniques and systemconfigurations of this disclosure, the artificial reality applicationrunning on artificial reality system 20 detects a gating gesture if hand132 is positioned substantially stationary for at least the thresholdperiod of time, and the digits of hand 132 are positioned such that suchthat the thumb and at least one other finger of hand 132 formapproximately a circle (e.g., an approximate ‘O’ shape, an approximate‘C’ shape, or a mirror image of an approximate ‘C’ shape).

According to other techniques and system configurations of thisdisclosure, the artificial reality application running on artificialreality system 20 detects a gating gesture if a particular surface ofthe wrist of the respective arm 134 is positioned substantiallystationary for at least the threshold period of time, and is in thefield of view (FoV) of HMD for at least the threshold period of time.According to some techniques of this disclosure, the artificial realityapplication running on artificial reality system 20 adds a displayelement (e.g., also referred to as an “assistant element” in thisdisclosure) to artificial reality content 122 output by HMD 112.According to these examples, artificial reality system 20 may detectcertain predefined gestures performed at locations generallycorresponding to the location of the display element to gate UI elementswithin artificial reality content 122. Examples of gating gestures thatartificial reality system 20 may detect with respect to the display orassistant element include a grip-and-pull from the wrist of an oppositearm (i.e. not arm 134) of the respective user 110C when thedisplay/assistant element is superimposed on a representation of thewrist of the opposite arm, a grip-and-throw of the display/assistantelement when the display/assistant element is presented as travelingwith the avatar of the respective user 110C in the virtual environmentrepresented by artificial reality content 122, or a grip-and-detach fromthe opposite arm when the display/assistant element is superimposed on arepresentation of the wrist of the other arm.

FIG. 2 is an illustration depicting an example HMD 112 configured tooperate in accordance with the techniques of the disclosure. HMD 112 ofFIG. 2 may be an example of any of HMDs 112 of FIGS. 1A and 1B. HMD 112may be part of an artificial reality system, such as artificial realitysystems 10, 20 of FIGS. 1A, 1B, or may operate as a stand-alone, mobileartificial realty system configured to implement the techniquesdescribed herein.

In this example, HMD 112 includes a front rigid body and a band tosecure HMD 112 to a user. In addition, HMD 112 includes aninterior-facing electronic display 203 configured to present artificialreality content to the user. Electronic display 203 may include, be, orbe part of any suitable display technology, such as liquid crystaldisplays (LCD), quantum dot display, dot matrix displays, light emittingdiode (LED) displays, organic light-emitting diode (OLED) displays,cathode ray tube (CRT) displays, e-ink, or monochrome, color, or anyother type of display capable of generating visual output. In someexamples, the electronic display is a stereoscopic display for providingseparate images to each eye of the user. In some examples, the knownorientation and position of display 203 relative to the front rigid bodyof HMD 112 is used as a frame of reference, also referred to as a localorigin, when tracking the position and orientation of HMD 112 forrendering artificial reality content according to a current viewingperspective of HMD 112 and the user. In other examples, HMD may take theform of other wearable head mounted displays, such as glasses.

As further shown in FIG. 2, in this example, HMD 112 further includesone or more motion sensors 206, such as one or more accelerometers (alsoreferred to as inertial measurement units or “IMUs”) that output dataindicative of current acceleration of HMD 112, GPS sensors that outputdata indicative of a location of HMD 112, radar, or sonar that outputdata indicative of distances of HMD 112 from various objects, or othersensors that provide indications of a location or orientation of HMD 112or other objects within a physical environment. Moreover, HMD 112 mayinclude integrated image capture devices 138A and 138B (collectively,“image capture devices 138”), such as video cameras, laser scanners,Doppler® radar scanners, depth scanners, or the like, configured tooutput image data representative of the physical environment.

More specifically, image capture devices 138 capture image datarepresentative of objects in the physical environment that are within afield of view 130A, 130B of image capture devices 138, which typicallycorresponds with the viewing perspective of HMD 112. HMD 112 includes aninternal control unit 210, which may include an internal power sourceand one or more printed-circuit boards having one or more processors,memory, and hardware to provide an operating environment for executingprogrammable operations to process sensed data and present artificialreality content on display 203.

In one example, in accordance with the techniques described herein,control unit 210 is configured to identify, based on the sensed data, aspecific gesture or one or more combinations of gestures performed byuser 110. Control unit 210 may perform one or more particular actions inresponse to identifying or detecting the gesture or combination(s) ofgestures. For example, in response to one identified gesture, controlunit 210 may generate and render a specific user interface elementoverlaid on artificial reality content for display on electronic display203. As explained herein, in accordance with the techniques of thedisclosure, control unit 210 may perform object recognition within imagedata captured by image capture devices 138 to identify hand 132 (ordigits, such as fingers or thumb thereof), arm 134 (or the wristthereof) or another part of user 110, and track movements of theidentified part to identify pre-defined gestures performed by user 110.

In response to identifying a predefined gesture (or combination/sequencethereof), control unit 210 takes some action, such as gating a menu,selecting an option from an option set associated with a user interfaceelement (e.g., the aforementioned menu), translating the gesture intoinput (e.g., characters), launching an application or otherwisedisplaying content, and the like. In some examples, control unit 210dynamically gates (generates and presents) a user interface element,such as a menu, in response to detecting a pre-defined gesture specifiedas a “trigger” for revealing a user interface or a specific elementthereof, such as a menu of user-selectable options. In other examples,control unit 210 performs such functions in response to direction froman external device, such as console 106, which may perform, objectrecognition, motion tracking and gesture detection, or any part thereof.

As one example, in accordance with various aspects of this disclosure,control unit 210 may gate the UI element(s) in response to detecting asingle-handed gesture performed by hand 132 in which two digits formapproximately a right angle (e.g. to form approximately an ‘L’ shape ora mirror image of an approximate ‘L’ shape). According to othertechniques and system configurations of this disclosure, control unit210 detects or identifies a gating gesture if hand 132 is positionedsubstantially stationary for at least the threshold period of time, andthe digits of hand 132 are positioned such that the thumb and at leastone other finger of hand 132 form approximately a circle (e.g., anapproximate ‘O’ shape, an approximate ‘C’ shape, or a mirror image of anapproximate ‘C’ shape).

As additional examples, according to other techniques and systemconfigurations of this disclosure, control unit 210 detects oridentifies a gating gesture if a particular surface of the wrist of arm134 is positioned substantially stationary for at least the thresholdperiod of time, and is in the FoV of HMD 112 for at least the thresholdperiod of time. According to some aspects of this disclosure, controlunit 210 adds a display element (e.g., also referred to as an “assistantelement” at times in this disclosure) to artificial reality content 122output by HMD 112. According to these examples, control unit 210 maydetect certain predefined gestures performed at locations generallycorresponding to the location of the display element to gate UI elementswithin artificial reality content 122 displayed via HMD 112.

Examples of gating gestures that control unit 210 may detect withrespect to the display or assistant element include a grip-and-pull fromthe wrist of the other arm (i.e. not arm 134) of user 110 when thedisplay/assistant element is superimposed on a representation of thewrist of the other arm, a grip-and-throw of the display/assistantelement when the display/assistant element is presented as travelingwith the avatar of the respective user 110 in the virtual environmentrepresented by artificial reality content 122, or a grip-and-detach fromthe other arm when the display/assistant element is superimposed on arepresentation of the wrist of the other arm.

FIG. 3 is a block diagram showing example implementations of console 106and head mounted display 112 of artificial reality system 10, 20 ofFIGS. 1A, 1B. In the example of FIG. 3, console 106 performs posetracking, gesture detection, and user interface generation and renderingfor HMD 112 in accordance with the techniques described herein based onsensed data, such as motion data and image data received from HMD 112and/or external sensors.

In this example, HMD 112 includes one or more processors 302 and memory304 that, in some examples, provide a computer platform for executing anoperating system 305, which may be an embedded, real-time multitaskingoperating system, for instance, or other type of operating system. Inturn, operating system 305 provides a multitasking operating environmentfor executing one or more software components 307, including applicationengine 340. As discussed with respect to the example of FIG. 2,processors 302 are coupled to electronic display 203, motion sensors 206and image capture devices 138. In some examples, processors 302 andmemory 304 may be separate, discrete components. In other examples,memory 304 may be on-chip memory collocated with processors 302 within asingle integrated circuit.

In general, console 106 is a computing device that processes image andtracking information received from cameras 102 (FIG. 1B) and/or HMD 112to perform gesture detection and user interface generation for HMD 112.In some examples, console 106 is a single computing device, such as aworkstation, a desktop computer, a laptop, or gaming system. In someexamples, at least a portion of console 106, such as processors 312and/or memory 314, may be distributed across a cloud computing system, adata center, or across a network, such as the Internet, another publicor private communications network, for instance, broadband, cellular,Wi-Fi, and/or other types of communication networks for transmittingdata between computing systems, servers, and computing devices.

In the example of FIG. 3, console 106 includes one or more processors312 and memory 314 that, in some examples, provide a computer platformfor executing an operating system 316, which may be an embedded,real-time multitasking operating system, for instance, or other type ofoperating system. In turn, operating system 316 provides a multitaskingoperating environment for executing one or more software components 317.Processors 312 are coupled to one or more I/O interfaces 315, whichprovides one or more I/O interfaces for communicating with externaldevices, such as a keyboard, game controllers, display devices, imagecapture devices, HMDs, and the like. Moreover, the one or more I/Ointerfaces 315 may include one or more wired or wireless networkinterface controllers (NICs) for communicating with a network, such asnetwork 104. Each of processors 302, 312 may comprise any one or more ofa multi-core processor, a controller, a digital signal processor (DSP),an application specific integrated circuit (ASIC), a field-programmablegate array (FPGA), processing circuitry (e.g., fixed function circuitryor programmable circuitry or any combination thereof) or equivalentdiscrete or integrated logic circuitry. Memory 304, 314 may comprise anyform of memory for storing data and executable software instructions,such as random-access memory (RAM), read only memory (ROM), programmableread only memory (PROM), erasable programmable read only memory (EPROM),electronically erasable programmable read only memory (EEPROM), andflash memory.

Software applications 317 of console 106 operate to provide an overallartificial reality application. In this example, software applications317 include application engine 320, rendering engine 322, gesturedetector 324, pose tracker 326, and user interface engine 328. Ingeneral, application engine 320 includes functionality to provide andpresent an artificial reality application, e.g., a teleconferenceapplication, a gaming application, a navigation application, aneducational application, training or simulation applications, and thelike. Application engine 320 may include, for example, one or moresoftware packages, software libraries, hardware drivers, and/orApplication Program Interfaces (APIs) for implementing an artificialreality application on console 106. Responsive to control by applicationengine 320, rendering engine 322 generates 3D artificial reality contentfor display to the user by application engine 340 of HMD 112.

Application engine 320 and rendering engine 322 construct the artificialcontent for display to user 110 in accordance with current poseinformation for a frame of reference, typically a viewing perspective ofHMD 112, as determined by pose tracker 326. Based on the current viewingperspective, rendering engine 322 constructs the 3D, artificial realitycontent which may in some cases be overlaid, at least in part, upon thereal-world 3D environment of user 110. During this process, pose tracker326 operates on sensed data received from HMD 112, such as movementinformation and user commands, and, in some examples, data from anyexternal sensors 90 (FIGS. 1A, 1B), such as external cameras, to capture3D information within the real-world environment, such as motion by user110 and/or feature tracking information with respect to user 110. Basedon the sensed data, pose tracker 326 determines a current pose for theframe of reference of HMD 112 and, in accordance with the current pose,constructs the artificial reality content for communication, via the oneor more I/O interfaces 315, to HMD 112 for display to user 110.

Moreover, based on the sensed data, gesture detector 324 analyzes thetracked motions, configurations, positions, and/or orientations ofobjects (e.g., hands, arms, wrists, fingers, palms, thumbs) of the userto identify one or more gestures performed by user 110. Morespecifically, gesture detector 324 analyzes objects recognized withinimage data captured by image capture devices 138 of HMD 112 and/orsensors 90 and external cameras 102 to identify a hand and/or arm ofuser 110, and track movements of the hand and/or arm relative to HMD 112to identify gestures performed by user 110. Gesture detector 324 maytrack movement, including changes to position and orientation, of thehand, digits, and/or arm based on the captured image data, and comparemotion vectors of the objects to one or more entries in gesture library330 to detect a gesture or combination of gestures performed by user110. Some entries in gesture library 330 may each define a gesture as aseries or pattern of motion, such as a relative path or spatialtranslations and rotations of a user's hand, specific fingers, thumbs,wrists and/or arms. Some entries in gesture library 330 may each definea gesture as a configuration, position, and/or orientation of the user'shand and/or arms (or portions thereof) at a particular time, or over aperiod of time. Other examples of type of gestures are possible. Inaddition, each of the entries in gesture library 330 may specify, forthe defined gesture or series of gestures, conditions that are requiredfor the gesture or series of gestures to trigger an action, such asspatial relationships to a current field of view of HMD 112, spatialrelationships to the particular region currently being observed by theuser, as may be determined by real-time gaze tracking of the individual,types of artificial content being displayed, types of applications beingexecuted, and the like.

Each of the entries in gesture library 330 further may specify, for eachof the defined gestures or combinations/series of gestures, a desiredresponse or action to be performed by software applications 317. Forexample, in accordance with the techniques of this disclosure, certainspecialized gestures may be pre-defined such that, in response todetecting one of the pre-defined gestures, user interface engine 328dynamically generates a user interface as an overlay to artificialreality content being displayed to the user, thereby allowing the user110 to easily invoke a user interface for configuring HMD 112 and/orconsole 106 even while interacting with artificial reality content. Inother examples, certain gestures may be associated with other actions,such as providing input, selecting objects, launching applications, andthe like.

In accordance with some examples of the system configurations andtechniques of this disclosure, gesture detector 324 determines whetheran identified motion and/or configuration of objects (e.g., hands, arms,wrists, fingers, palms, thumbs) of the user corresponds to a predefinedgesture defined by one of a plurality of entries in gesture library 330.Each of the entries of gesture library 330 may define a differentgesture as a specific motion, configuration, position, and/ororientation of a user's hand, digit (finger or thumb) and/or arm overtime, or a combination of such properties. In addition, each of thedefined gestures may be associated with a desired response in the formof one or more actions to be performed by other components of console106 and/or HMD 112.

As one example, one or more of the predefined gestures in gesturelibrary 330 may trigger the generation, transformation, and/orconfiguration of one or more user interface elements, by UI engine 328.Rendering engine 322 may render and overlay the UI element(s) that UIengine 328 generates based on gesture detector 324 detecting thepredefined gesture(s). In some examples, UI engine 328 and renderingengine 322 may define a location and/or orientation of the UI element(discussed by way of the example of UI menu 124) in artificial realitycontent 122 communicated to HMD 112.

According to some of the techniques described herein, UI engine 328 andrendering engine 322 perform UI element gating in response to gesturedetector 324 identifying one or more gestures in which hand 132 isconfigured such that two of the digits form approximately a right angle.For example, gesture detector 324 identifies the gating gesture if anindex finger and a thumb of hand 132 form approximately a right angle.In some examples, gesture detector 324 adds a temporal component to thecriteria for the gating gesture to be recognized. That is, gesturedetector 324 may identify the gesture if the configuration of hand 132is substantially stationary for at least a threshold period of time, andduring the period of time during which hand 132 is stationary, and hand132 is positioned such that the index finger and the thumb of hand 132form approximately a right angle. It will be appreciated that, while theposition of hand 132 is described herein as forming an “angle” asrepresented by a turn between two straight lines, gesture detector 324adjusts the angle determination of this disclosure to accommodate humananatomical idiosyncrasies, such as the curvature of the webbing betweenthe thumb and index finger, any natural bends caused by inter-phalangejoints of the fingers of hand 132, etc.

In some examples, gesture detector 324 identifies different gatinggestures based on the orientation of hand 132 when the index finger andthumb are positioned approximately at the right angle. For example,gesture detector 324 may identify one gating gesture if a back surfaceof hand 132 is facing image capture devices 138, and may identify adifferent gating gesture if a palm of hand 132 is facing image capturedevices 138. As another example, gesture detector 324 may identify onegating gesture if the thumb of hand 132 is facing upwards in the viewcaptured by image capture devices 138, and may identify a differentgating gesture if the index finger of hand 132 is facing upwards in theview captured by image capture devices 138. In some examples, artificialreality system 10 may recognize the particular gestures based on acombination of the various orientation attributes of hand 132 describedabove.

In these examples, UI engine 328 may generate the UI element such thatthe approximate apex of the angle formed between the index finger andthe thumb generally indicates the location of a corner of the UIelement. In one example, assuming that hand 132 is the right hand ofuser 110, UI engine 328 may generate the UI element such that the apexof the angle between the index finger and thumb of hand 132 indicatesthe location of the bottom right corner of the UI element. Conversely,in one example, assuming that hand 132 is the left hand of user 110, UIengine 328 may generate the UI element such that the apex of the anglebetween the index finger and thumb of hand 132 indicates the location ofthe bottom left corner of the UI element.

Additionally, UI engine 328 may edit one or more of the orientation, thegranularity, the content, etc. of the UI element if gesture detector 324detects a change in the orientation of hand 132 while the index fingerand thumb form the approximate right angle. For example, UI engine 328may gate the UI element as a menu in portrait orientation if gesturedetector 324 detects that the index finger of hand 132 is pointingupward and the back of hand 132 is facing image capture devices 138. Inthis example, UI engine 328 may switch the menu to have a landscapeorientation if gesture detector 324 detects that the orientation of hand132 has changed such that the thumb of hand 132 is facing upward and thepalm of hand 132 is facing image capture devices 138.

In some such examples, UI engine 328 may also change the contents of themenu based on the change in the orientation of hand 132 as identified bygesture detector 324. For example, UI engine 328 may edit the menu toinclude user-selectable options that provide a finer-grained set ofuser-selectable options in the landscape-oriented menu in comparison tothe portrait-oriented menu. For instance, UI engine 328 may generate thelandscape-oriented menu as a drilldown menu that shows a deeper level ofuser-selectable options than the portrait-oriented menu. In someexamples, UI engine 328 may be configured to gate the UI element byidentifying a top right or top left corner of the UI element if gesturedetector 324 detects a configuration of hand 132 that is inverted incomparison to the ‘L’ or mirror-image ‘L’ configurations describedabove.

According to some techniques of this disclosure, gesture detector 324detects a gating gesture if hand 132 is positioned substantiallystationary for at least the threshold period of time, and the digits ofhand 132 are positioned such that such that the thumb and at least oneother finger of hand 132 form approximately a circle or approximately acircular segment. In some examples, gesture detector 324 may detect thegesture if the view of hand 132 facing image capture devices 138 is asideways orientation, and represents the side of hand 132 on which thethumb is located. For instance, the normal drawn from image capturedevices 138 to hand 132 may intersect with the inside area of the circleor circular segment formed by the thumb and the other finger(s) of hand132. In some of these implementations, UI engine 328 may position movingpictures to play a video within the circle or circular segment formed byhand 132, thereby creating the effect of a “video passthrough” withinthe overall virtual environment represented by artificial realitycontent 122. In other implementations, UI engine 328 may display a UIelement, such as a menu of user-selectable options within or at alocation generally corresponding to the circle or circular segmentformed by hand 132. Rendering engine 322 is configured to renderartificial reality content 122 for output via electronic display 203,both with and without the various UI elements generated by UI engine 328in response to the gestures detected by gesture detector 324.

According to some techniques of this disclosure, gesture detector 324detects a gating gesture if a portion of arm 134 is positionedsubstantially stationary for at least the threshold period of time, andis in the FoV of HMD 112 for at least the threshold period of time. Forexample, gesture detector 324 may detect the gesture if theconfiguration of arm 134 is such that the wrist is substantiallystationary for at least a threshold period of time, and the wrist ispositioned such that a normal from the wrist faces HMD 112. In someexamples, gesture detector 324 may detect the gesture if the view of arm134 facing HMD 112 is a sideways orientation, and represents the innerside of the wrist, i.e. the side on which the thumb of hand 132 islocated. For instance, the normal drawn from HMD 112 to arm 134 mayintersect with the inside surface of the wrist. In some of theseimplementations, UI engine 328 may generate a UI element, such as amenu, which rendering engine 322 renders as being superimposed on arepresentation of the wrist within the virtual environment representedby artificial reality content 122.

According to some techniques of this disclosure, UI engine 328 includesa display element within artificial reality content 122, enablinggesture detector 324 to identify gestures performed with respect to thedisplay element. In these examples, gesture detector 324 may detectcertain predefined gestures performed at locations generallycorresponding to the location of the display element within the virtualenvironment, and UI engine 324 may gate UI elements in response togesture detector 324 detecting one or more of these predefined gesturesat the location corresponding to the location of the display element. Assuch, the display element may be considered an “assistant” or “personalassistant” that travels with an avatar representing user 110 within thevirtual environment represented by artificial reality content 122.According to various aspects of this disclosure UI engine 328 may causerendering engine 322 to render the assistant element as being attachedto the virtual body of the avatar, or as being detached from andfollowing the avatar.

In some examples, rendering engine 322 may generate the assistantelement to appear detached from the avatar, and to follow the avatar'smovements within the virtual environment represented by artificialreality content 122. According to these examples, the assistant elementsimulates a drone that hovers above or floats alongside the avatar ofuser 110 in the virtual environment represented by artificial realitycontent 122. In these implementations, gesture detector 324 may detectthe gating gesture based on a grip-and-throw combination performed byhand 132 with respect to the assistant element included in artificialreality content 122.

For example, gesture detector 324 may identify the gating gesturecontingent on detecting a combination of (1) a gripping motion of two ormore digits of hand 132 to form a gripping configuration at a locationthat corresponds to the assistant element within the virtual environmentrepresented by artificial reality content 122, and (ii) a throwingmotion of hand 132 with respect to the assistant element, where thethrowing motion occurs subsequently to the gripping motion.

For instance, artificial reality system 10 may detect the throwingmotion by identifying a combination of a release of the grippingconfiguration of hand 132 and a particular movement of hand 132 and/orarm 134. The particular movement that accompanies, follows, or partiallyoverlaps with the release of the gripping configuration may include aflexion of the wrist of arm 134 and/or of joints of hand 132, an outwardflicking motion of at least one of the digits of hand 132, or variouspermutations/combination thereof.

In some examples, rendering engine 322 may render the assistant elementas being attached to a wrist of the avatar. For instance, renderingengine 322 may render the assistant element as being attached to thewrist of a non-dominant arm, such as the left arm in a scenario in whicharm 134 represents dominant right arm of user 110. In these examples,the assistant element may simulate a wearable item, in that theassistant element is rendered as being presently attached to, butpotentially detachable from, the other arm of user 110. For instance,rendering engine 322 may render the display element at a locationcorresponding to a representation of user 110's other arm (i.e., the armother arm 134), which may, in some examples represent the non-dominantarm of user 110. In some such implementations, gesture detector 324 maydetect a gesture that includes a grip-and-move combination, agrip-and-release combination, a grip-move-release combination, or simplya grip performed by hand 132 with respect to the assistant element thatappears superimposed on and attached to the other arm of user 110.

For example, gesture detector 324 may detect the gesture by identifyinga gripping motion of hand 132 with respect to the display element, andin response, UI engine 328 and rendering engine 322 may update theappearance of the display element to appear detached from and separatefrom the other arm of user 110. In some examples, gesture detector 324may detect a release of the gripping configuration of hand 132 at alocation that is some distance away from the other arm of user 110, i.e.the arm from which the assistant element was removed, as represented inthe virtual environment. In turn, UI engine 328 may cause renderingengine 322 to display the assistant element at approximately thelocation where the gripping configuration of hand 132 was released. Inthis example, gesture detector 324 leverages a single-handed gesture,thereby alleviating user burdens associated with double-handed gestures.

Additionally, based on gesture detector 324 identifying the release ofthe gripping configuration of hand 132, UI engine 328 may gate a UIelement, such as a menu of user-selectable options. For example, UIengine 328 may cause rendering engine 322 to render the menu such thatthe menu is positioned next to or otherwise in the general vicinity ofthe assistant element, while the assistant element appears suspended atthe location where the gripping configuration of hand 132 was released.In some examples, gesture detector 324 may subsequently detect agrip-and-move gesture of hand 132 with respect to the assistant element,such that the display element is moved back to the wrist of the otherarm of user 110. In these examples, UI engine 328 may remove the menufrom artificial reality content 122, thereby causing rendering engine322 to cease rendering the menu within the virtual environment.

In some implementations, gesture detector 324 may detect a grip-and-pullcombination or a pinch-and-pull combination with respect to the displayelement that originates at a predefined area of the other arm of user110, such as at the wrist of the other arm. According to theseimplementations, UI engine 328 may gate a UI menu of user-selectableoptions, in response to gesture detector 324 identifying any of thesemovements. According to some of these implementations, UI engine 328 andrendering engine 322 may change the content, form factor, or selectiongranularity of the menu in response to gesture detector 324 detectingdifferent lengths of pulling from the other arm's wrist.

For instance, UI engine 328 and rendering engine 322 of artificialreality system 10 may gate the UI menu by modifying the UI element, inresponse to identifying a grip-and-pull combination motion of hand 132with respect to the UI element (e.g., an example of the assistantelement described above) virtually overlaid on the wrist. If gesturedetector 324 identifies a gripping motion of two or more digits of hand132 to form a gripping configuration, and a subsequent pulling motion ofthe same two or more digits away from the wrist of the other hand, whilethe same two or more digits are in the gripping configuration, then UIengine 328 may cause rendering engine 322 to output a menu, such as acircular menu.

In this way, these particular aspects of this disclosure described abovesimulate a drawer or filing cabinet in terms of invoking UI elements. Ifgesture detector 324 identifies a stoppage in the pulling motion whilethe gripping configuration is still intact, followed by a furtherpulling motion with the gripping configuration still intact, then UIengine 328 may make updates to the menu, and cause rendering engine 122to output the updated menu via artificial reality content 122. In someexamples, rendering engine 322 may position the original menu and theupdated menu at different locations, such as at the locations where thecorresponding pulling motion ceased.

Accordingly, the techniques and system configurations of this disclosureprovide specific technical improvements to the computer-related field ofrendering and displaying content by an artificial reality system. Forexample, the artificial reality system of FIG. 3 may provide ahigh-quality artificial reality experience to a user, such as user 110,by generating and rendering user interface elements overlaid on theartificial reality content based on detection of intuitive, yetdistinctive, gestures performed by the user.

Further, systems as described herein may be configured to detect certaingestures based on hand and arm movements that are defined to avoidtracking occlusion. Tracking occlusion may occur when one hand of theuser at least partially overlaps the other hand, making it difficult toaccurately track the individual digits (fingers and thumb) on each hand,as well as the position and orientation of each hand. Systems asdescribed herein, therefore, may be configured to primarily detectsingle-handed or single arm-based gestures. The use of single-handed orsingle arm-based gestures may further provide enhanced accessibility tousers having large- and fine-motor skill limitations. Furthermore,systems as described herein may be configured to detect double-handed ordouble arm-based gestures in which the hands of the user do not interactor overlap with each other.

FIG. 4 is a block diagram depicting an example in which gesturedetection and user interface generation is performed by HMD 112 of theartificial reality systems of FIGS. 1A, 1B in accordance with thetechniques of the disclosure.

In this example, similar to FIG. 3, HMD 112 includes one or moreprocessors 302 and memory 304 that, in some examples, provide a computerplatform for executing an operating system 305, which may be anembedded, real-time multitasking operating system, for instance, orother type of operating system. In turn, operating system 305 provides amultitasking operating environment for executing one or more softwarecomponents 417. Moreover, processor(s) 302 are coupled to electronicdisplay 203, motion sensors 206, and image capture devices 138.

In the example of FIG. 4, software components 417 operate to provide anoverall artificial reality application. In this example, softwareapplications 417 include application engine 440, rendering engine 422,gesture detector 424, pose tracker 426, and user interface engine 428.In various examples, software components 417 operate similar to thecounterpart components of console 106 of FIG. 3 (e.g., applicationengine 320, rendering engine 322, gesture detector 324, pose tracker326, and user interface engine 328) to construct user interface elementsoverlaid on, or as part of, the artificial content for display to user110 in accordance with detected gestures of user 110. In some examples,rendering engine 422 constructs the 3D, artificial reality content whichmay be overlaid, at least in part, upon the real-world, physicalenvironment of user 110.

Similar to the examples described with respect to FIG. 3, based on thesensed data, gesture detector 424 analyzes the tracked motions,configurations, positions, and/or orientations of objects (e.g., hands,arms, wrists, fingers, palms, thumbs) of the user to identify one ormore gestures performed by user 110. In accordance with the techniquesof the disclosure, user interface engine 428 generates user interfaceelements as part of, e.g., overlaid upon, the artificial reality contentto be displayed to user 110 and/or performs actions based on one or moregestures or combinations of gestures of user 110 detected by gesturedetector 424. More specifically, gesture detector 424 analyzes objectsrecognized within image data captured by image capture devices 138 ofHMD 112 and/or sensors 90 or external cameras 102 to identify a handand/or arm of user 110, and track movements of the hand and/or armrelative to HMD 112 to identify gestures performed by user 110. Gesturedetector 424 may track movement, including changes to position andorientation, of the hand, digits, and/or arm based on the captured imagedata, and compare motion vectors of the objects to one or more entriesin gesture library 430 to detect a gesture or combination of gesturesperformed by user 110.

Gesture library 430 is similar to gesture library 330 of FIG. 3. Each ofthe entries in gesture library 430 may specify, for the defined gestureor series of gestures, conditions that are required for the gesture totrigger an action, such as spatial relationships to a current field ofview of HMD 112, spatial relationships to the particular regioncurrently being observed by the user, as may be determined by real-timegaze tracking of the individual, types of artificial content beingdisplayed, types of applications being executed, and the like.

In response to detecting a matching gesture or combination of gestures,HMD 112 performs the response or action assigned to the matching entryin gesture library 430. For example, in accordance with the techniquesof this disclosure, certain specialized gestures may be pre-defined suchthat, in response to gesture detector 424 detecting one of thepre-defined gestures, user interface engine 428 dynamically generates auser interface as an overlay to artificial reality content beingdisplayed to the user, thereby allowing the user 110 to easily invoke auser interface for configuring HMD 112 while viewing artificial realitycontent. In other examples, in response to gesture detector 424detecting one of the pre-defined gestures, user interface engine 428and/or application engine 440 may receive input, select values orparameters associated with user interface elements, launch applications,modify configurable settings, send messages, start or stop processes orperform other actions.

Various gestures that gesture detector 424 may identify from the imagedata captured by image capture devices 138 include ‘L’ shapedconfigurations of hand 132, grip- and pull movements performed by hand132, and grip-and-throw movements performed by hand 132. Another exampleof a gesture that gesture detector 424 may identify from the image datais a wrist-gazing gesture, in which the wrist of the opposite arm ofuser 110 is placed in the FoV of HMD 112 for at least a threshold periodof time, and is substantially stationary for at least the thresholdperiod of time. UI engine 428 and rendering engine 422 may gate variousUI elements, such as menus of user-selectable options, in response togesture detector 424 identifying any of the predefined gestures of thisdisclosure. In some examples, UI engine 428 and rendering engine 422 mayremove a previously-gated UI element in response to gesture detector 424identifying a subsequent “de-gating” gesture from the image data.

FIG. 5 is a flowchart illustrating a process 450 that artificial realitysystems 10, 20 and/or components thereof may perform in accordance withthe gesture-driven UI element gating techniques of this disclosure.While FIG. 5 illustrates various steps in particular order/sequence asan example, it will be appreciated that artificial reality systems 10,20 may perform the illustrated steps in various orders/sequences,including partial or total concurrencies, and may iterate various stepsa number of times. UI engines 328, 428 and rendering engines 322, 422may output artificial reality content 122 (452). For example, UI engines328, 428 and rendering engines 322, 422 may output artificial realitycontent 122 via electronic display 203 to generate a virtualenvironment.

Image capture devices 138 and/or external cameras 102 may capture imagedata (454). The image data may reflect the physical environmentsurrounding user 110. Gesture detectors 324, 424 may determine whether apredefined gesture is detected within the FoV of HMD 112 (decision block456). For instance, gesture detectors 324, 424 may process the imagedata received from image capture devices 138 and/or external cameras 102to determine whether one or more of the hand/arm configurations and/ormotions/movements detected from the image data match an entry of gesturelibraries 330, 430.

If gesture detectors 324, 424 do not identify a predefined gesture fromthe image data (NO branch of decision block 456), artificial realitysystems 10, 20 may continue to output artificial reality content 122 andcapture image data from the physical environment of user 110(effectively iterating steps 452 and 454). If gesture detectors 324, 424identify a predefined gesture from the image data (YES branch ofdecision block 456), then UI engines 328, 428 and rendering engines 322,422 may gate one or more UI elements (458) in accordance with thegesture-driven UI element gating techniques of this disclosure. Variousexamples of predefined gestures and UI elements that can be gated inaccordance with the techniques of this disclosure are described below infurther detail.

FIGS. 6A-11 are conceptual diagrams illustrating various movements andconfigurations of hand 132 (and in some cases, the wrist of arm 134)that gesture detectors 324, 424 may use to identify various predefinedgating gestures according to aspects of this disclosure. The wrist ofarm 134 is labeled as wrist 135 in some of FIGS. 5A-10, the other arm ofuser 110 is labeled as opposite arm 934, and the wrist of the other armis labeled as opposite wrist 902.

FIGS. 6A-6D illustrate corner-based gating configurations of hand 132and UI elements that artificial reality systems 10, 20 may invoke inresponse to the identification of the corner-based gating configurationsof hand 132. FIG. 6A illustrates configuration 502 of hand 132 thatgesture detectors 324, 424 may identify, in response to which UI engines328, 428 may gate a UI element based on configuration 502 identifyingthe approximate location of a corner of the UI element. As shown in FIG.6A, configuration 502 entails an approximate right angle between theindex finger and thumb of hand 132. That is, image capture devices 138and/or external cameras 102 may capture image data representative of aphysical environment of user 110, and electronic display 203 may outputartificial reality content. Gesture detectors 328, 428 may identify,from the image data, a gesture comprising configuration 502 in whichhand 132 is substantially stationary for at least a threshold period oftime and positioned such that an index finger and a thumb of hand 132form approximately a right angle. UI engines may generate a UI elementin response to the identified gesture, and rendering engines 322, 422may render the UI element as an overlay to the artificial realitycontent. In the case of configuration 502, the index finger of hand 132points upward in the field of view (FoV) of HMD 112, and the back ofhand 132 faces image capture devices 138. Based on gesture detectors322, 422 detecting hand 132 being in configuration 502 for at least thethreshold period of time, UI engines 328, 428 may cause renderingengines 322, 422 to render the UI element according to a portraitorientation.

FIG. 6B illustrates another configuration 504 of hand 132 that gesturedetectors 324, 424 may identify, in response to which UI engines 328,428 may gate a UI element based on configuration 504 identifying theapproximate location of a corner of the UI element. In the case ofconfiguration 504, the thumb of hand 132 points upward in the viewcaptured by image capture devices 138, and the palm of hand 132 facesHMD 112. Based on gesture detectors 322, 422 detecting hand 132 being inconfiguration 504 for at least the threshold period of time, UI engines328, 428 may cause rendering engines 322, 422 to render the UI elementaccording to a landscape orientation. Configuration 504 represents a90-degree hand rotation and a 180-degree hand reflection with respect toconfiguration 502.

FIG. 6C illustrates menu 506 that UI engines 328, 428 and renderingengines 322, 422 may gate in response to gesture detectors 324, 424identifying a gesture in which hand 132 conforms to configuration 502for at least the threshold period of time. As shown in FIG. 6C, UIengines 328, 428 and rendering engines 322, 422 gate menu 506 accordingto a portrait orientation, in response to gesture detectors 324, 424determining that hand 132 conforms to configuration 502 for at least thethreshold period of time.

FIG. 6D illustrates menu 508 that that UI engines 328, 428 and renderingengines 322, 422 may gate in response to gesture detectors 324, 424identifying a gesture in which hand 132 conforms to configuration 504for at least the threshold period of time. As shown in FIG. 6D, UIengines 328, 428 and rendering engines 322, 422 gate menu 508 accordingto a landscape orientation, in response to gesture detectors 324, 424determining that hand 132 conforms to configuration 504 for at least thethreshold period of time.

In some use case scenarios, gesture detectors 324, 424 may detect atransition of hand 132 from configuration 502 to configuration 504 asthe performance of two separate, sequential gestures. As such, gesturedetectors 324, 424 may identify two separate gestures based on theposition of hand 132 conforming to configuration 502 and the position ofhand conforming to configuration 504. In this particular use casescenario, gesture detectors 324, 424 identify the first gesture based onthe first position (conforming to configuration 502) being detectedprior to the second gesture based on the second position (conforming toconfiguration 504) being detected. In this case, UI engines 328, 428 andrendering engines 322, 422 may modify menu 506, which conforms to afirst (portrait) orientation to form menu 508, which conforms to asecond (landscape) orientation. In the examples illustrated in FIGS. 6Cand 6D, menu 506 (conforming to the first, i.e. portrait, orientation)includes a subset of user-selectable options included in menu 508(conforming to the second, i.e. landscape, orientation).

In the particular examples of FIGS. 6C and 6D, UI engines 328, 428interpret the data provided by gesture detectors 324, 424 to determinethat each of the gestures in which hand 132 conforms to configurations502, 504 indicates the location of the lower-right corner of menus 506,508, respectively. However, it will be appreciated that, in otherexamples, UI engines 328, 428 and rendering engines 322, 422 mayidentify the lower-left, upper-left, or upper-right corners of variousUI elements based on the information provided by gesture detectors 324,424. In each of FIGS. 6C and 6D, UI engines 328, 428 and renderingengines 322, 422 render menus 506 and 508 such that the long side of therespective menu 506, 508 substantially aligns with the index finger ofhand 132.

FIGS. 7A and 7B illustrate rounded-boundary configurations of hand 132that artificial reality systems 10, 20 may detect as stimuli for gatingcertain UI elements within the virtual environment represented byartificial reality content 122. FIG. 7A illustrates configuration 602,in which the index finger and thumb of hand 132 form a circular segmentor approximately a circular segment. The circular segment ofconfiguration 602 generally represents an arc that, if extended fromboth open ends, would potentially form an enclosed space, such as acircle or approximately a circle. Gesture detectors 324, 424 mayidentify the gating gesture illustrated in FIG. 7A if hand 132 conformsto configuration 602 and remains in configuration 602 for at least athreshold period of time. That is, gesture detectors 324, 424 identifythe gating gesture of FIG. 7A if the positioning of hand 132 satisfiesboth of the conditions of remaining substantially stationary for atleast the threshold period of time, and two of the digits of hand 132are positioned such that the two digits form the circular segment ofconfiguration 602.

To aid in the user experience and based on the general structure of thehuman hand, gesture detectors 324, 424 may detect the gating gesture ifthe thumb of hand 132 forms the circular segment in combination with atleast one other finger (other than the thumb) during the thresholdperiod of time. The examples of this disclosure are directed to theindex finger and thumb of hand 132 forming the circular segment.However, it will be appreciated that gesture detectors 324, 424 mayidentify the gating gesture based on the thumb forming the circularsegment with various fingers, such as just the index finger, with allfour other fingers by way of the index finger occluding the remainingfingers, or with any one or more of the remaining fingers other than thethumb and index finger.

The circular segment formed by hand 132 in accordance with configuration602 includes enclosed area 604A. In some examples, gesture detectors324, 424 may identify the gating gesture if hand 132 is positioned suchthat a normal from anywhere in enclosed area 604A within the circularsegment of configuration 602 is facing HMD 112. In these examples, UIengines 328, 428 generate a UI element in response to gesture detectors324, 424 identifying the gating gesture illustrated in FIG. 7A, and maycause rendering engines 322, 422 to render the UI element as an overlaywith respect to a portion of the virtual environment represented byartificial reality content 122.

For example, rendering engines 322, 422 may render the UI element (e.g.,content) generated by UI engines 328, 428 to appear within enclosed area604A or at least partially within enclosed area 604A. In some examples,UI engines 328, 428 generate the UI element to include a reproduction ofa portion of the image data representative of the physical environmentcaptured by image capture devices 138 and/or external cameras 102. Inthese examples, artificial reality systems 10, 20 implement thetechniques of this disclosure to provide a “passthrough” effect byreproducing the actual physical environment of user 110 within thecircular segment, while maintaining the remainder of the virtualenvironment represented by artificial reality content 122. In oneexample, UI engines 328, 428 and rendering engines 322, 422 generate andrender the portion of the image data included in the UI element suchthat the image data corresponds to a portion of the physical environmentthat lies along the normal from enclosed area 604A within the circularsegment facing HMD 112.

In other examples, UI engines 328, 428 generate the UI element toinclude video data, such as moving pictures. In these examples,artificial reality systems 10, 20 implement the techniques of thisdisclosure to provide a video “passthrough” effect or video “overlay”effect by playing the video within the circular segment, whilemaintaining the remainder of the virtual environment represented byartificial reality content 122. In other examples still, UI engines 328,428 generate the UI element to include a menu of user-selectableoptions. In these examples, artificial reality systems 10, 20 implementthe techniques of this disclosure to provide menu invocationfunctionalities within the circular segment, while maintaining theremainder of the virtual environment represented by artificial realitycontent 122. In these examples, UI engines 328, 428 and renderingengines 322, 422 output content that is contained within a virtualwindow. Either a full boundary or a partial boundary of the virtualwindow is indicated by the inner ring formed by hand 132.

FIG. 7B illustrates configuration 606, in which the index finger andthumb of hand 132 form a circle or approximately a circle. The circle orapproximate circle of configuration 606 generally represents a closedshape that has a generally rounded boundary, after accounting fornon-smooth transitions caused by anatomical attributes of hand 132.Gesture detectors 324, 424 may identify the gating gesture illustratedin FIG. 7B if hand 132 conforms to configuration 606 and remains inconfiguration 606 for at least a threshold period of time. That is,gesture detectors 324, 424 identify the gating gesture of FIG. 7B if thepositioning of hand 132 satisfies both of the conditions of remainingsubstantially stationary for at least the threshold period of time, andtwo of the digits of hand 132 are positioned such that the two digitsform the circle of configuration 606.

To aid in the user experience and based on the general structure of thehuman hand, gesture detectors 324, 424 may detect the gating gesture ifthe thumb of hand 132 forms the circle in combination with at least oneother finger (other than the thumb) during the threshold period of time.The examples of this disclosure are directed to the index finger andthumb of hand 132 forming the circle. However, it will be appreciatedthat gesture detectors 324, 424 may identify the gating gesture based onthe thumb forming the circle with various fingers, such as just theindex finger, with all four other fingers by way of the index fingeroccluding the remaining fingers, or with any one or more of theremaining fingers other than the thumb and index finger.

The circle formed by hand 132 in accordance with configuration 606includes enclosed area 604B. In some examples, gesture detectors 324,424 may identify the gating gesture if hand 132 is positioned such thata normal from anywhere in enclosed area 604B within the circle ofconfiguration 606 is facing HMD 112. In these examples, UI engines 328,428 generate a UI element in response to gesture detectors 324, 424identifying the gating gesture illustrated in FIG. 7B, and may causerendering engines 322, 422 to render the UI element as an overlay withrespect to a portion of the virtual environment represented byartificial reality content 122.

For example, rendering engines 322, 422 may render the UI element (e.g.,content) generated by UI engines 328, 428 to appear within enclosed area604B or at least partially within enclosed area 604B. In some examples,UI engines 328, 428 generate the UI element to include a reproduction ofa portion of the image data representative of the physical environmentcaptured by image capture devices 138 and/or external cameras 102. Inthese examples, artificial reality systems 10, 20 implement thetechniques of this disclosure to provide a “passthrough” effect byreproducing the actual physical environment of user 110 within thecircle, while maintaining the remainder of the virtual environmentrepresented by artificial reality content 122. In one example, UIengines 328, 428 and rendering engines 322, 422 generate and render theportion of the image data included in the UI element such that the imagedata corresponds to a portion of the physical environment that liesalong the normal from enclosed area 604B within the circle facing HMD112.

In other examples, UI engines 328, 428 generate the UI element toinclude video data, such as moving pictures. In these examples,artificial reality systems 10, 20 implement the techniques of thisdisclosure to provide a video “passthrough” effect or video “overlay”effect by playing the video within the circle, while maintaining theremainder of the virtual environment represented by artificial realitycontent 122. In other examples still, UI engines 328, 428 generate theUI element to include a menu of user-selectable options. In theseexamples, artificial reality systems 10, 20 implement the techniques ofthis disclosure to provide menu invocation functionalities within thecircle, while maintaining the remainder of the virtual environmentrepresented by artificial reality content 122. In these examples, UIengines 328, 428 and rendering engines 322, 422 output content that iscontained within a virtual window. Either a full boundary or a partialboundary of the virtual window is indicated by the inner ring formed byhand 132.

FIGS. 8A and 8B illustrate configurations of arm 134 that artificialreality systems 10, 20 may detect as stimuli for gating certain UIelements within the virtual environment represented by artificialreality content 122. FIGS. 8A and 8B illustrate wrist 702, which is asegment or section of arm 134 that is immediately adjacent to hand 132.Gesture detectors 324, 424 may identify the gating gesture based on theconfiguration of arm 134 such that wrist 702 being substantiallystationary for at least a threshold period of time and positioned suchthat a normal from wrist 702 is facing HMD 112. For instance, the normalmay represent a straight line drawn from any point of wrist 702 to thefront rigid body of HMD 112. As such, FIG. 8A illustrates configuration704 in which wrist 702 is positioned, in relation to HMD 112, in such away that the imaginary normal drawn from wrist 702 intersects with thefront rigid body of HMD 112. The configuration of wrist 702 may simulateor be substantially the same as a wrist configuration while holding acontroller. In this way, artificial reality systems 10, 20 leverage anatural position for users, and may enable UI element gating even if theuser is holding one or more controllers.

FIG. 8B illustrates a representation of hand 132 and wrist 702 in thevirtual reality environment represented by artificial reality content122. In response to gesture detectors 324, 424 identifying the gesturebased on wrist 702 being substantially stationary and along the normaldrawn from the front rigid body of HMD 112 for the threshold period oftime, UI engines 328, 428 may generate a UI element in response to theidentified gesture, and rendering engines 322, 422 may to render the UIelement overlaid on an image of wrist 702. The representation of wrist702 in the virtual environment with the UI element overlaid is shown byway of configuration 706 illustrated in FIG. 8B. In the example of FIG.8B, UI engines 328, 428 generate, and rendering engines 322, 422 render,the UI element in the form of menu 708. In other implementations, UIengines 328, 428 may generate different UI elements in response togesture detectors 324, 424 identifying the gesture indicated byconfiguration 704 in which wrist 702 is substantially stationary for atleast the threshold period of time and positioned such that the normalfrom wrist 702 is facing HMD 112.

In some instances, in which rendering engines 322, 422 overlay menu 708on the image of wrist 702, gesture detectors 324, 424 may detect a touchgesture at a portion of menu 708 that appears overlaid on the image ofwrist 702. For example, user 110 may use his/her other hand (not hand132) to select the portion of menu 708 and provide self-haptic feedbackby making contact or by occluding, in a contactless manner, a point ofwrist 702. In these examples, UI engines 328, 428 may map the contactpoint or occlusion point in the image data representing the physicalenvironment to a point on menu 708 as shown in the virtual environmentof artificial reality content 122. Based on the location of the mappedpoint on menu 708, artificial reality systems 10, 20 may identify aparticular user-selectable option to invoke, in response the inputreceived from user 110.

For example, artificial reality systems 10, 20 may invoke gesturedetectors 324, 424 to identify a selection gesture that indicates theinput described above. In response to gesture detectors 324, 424identifying the selection gesture, and based on the correspondingcoordinates of the haptic input on menu 708, UI engines 328, 428 maygenerate an updated UI element, e.g., in the form of menu 708 with aselected option and/or with a set of further selectable options in viewof the option that was previously selected via the selection input. Inthis way, artificial reality systems 10, 20 utilize the gesture of user110 gazing, uninterrupted, at his/her own wrist for a certain period oftime, to gate UI elements such as menu 708, thereby providing user 110with selectable options within the virtual environment represented byartificial reality content 122.

FIGS. 9A-9C illustrate various configurations of hand 132 that form agrip-and-throw gesture in response to which artificial reality systems10, 20 may gate UI elements, in accordance with some aspects of thisdisclosure. In various implementations of this disclosure, UI engines328, 428 may generate assistant element 802, and rendering engines 322,422 may output assistant element 802 via electronic display 203 toappear within the virtual environment represented by artificial realitycontent 122. UI engines 328, 428 and rendering engines 322, 422 mayoutput assistant element 802 to simulate a drone, in that assistantelement 802 may appear to hover over or alongside an avatar representinguser 110 in the virtual environment, and that navigates the virtualenvironment in synchrony with the avatar.

FIG. 9A illustrates gripping configuration 810 of hand 132. Gesturedetectors 324, 424 may identify a gesture that includes a grippingmotion of two or more digits of hand 132 to form gripping configuration810 at a location that corresponds to assistant element 802. Forinstance, gesture detectors 324, 424 may detect the completion of thegripping motion of hand 132 by determining that the thumb of hand 132 ata location that corresponds to a first portion of assistant element 802,and determining that at least one finger of hand 132 other than thethumb is at a location that corresponds to a second portion of assistantelement 802. For example, the first portion of assistant element 802 isat least approximately diametrically opposed to the second portion ofassistant element 802. In this way, gesture detectors 324, 424 maydetect the formation of gripping configuration 810 based on the digitsof hand 132 forming a pincer (tip-to-tip) grip around the virtuallocation of assistant element 802, a pinch (pad-to-pad) grip around thevirtual location of assistant element 802, a lumbrical grip (in whichthe digits contact locations corresponding to assistant element 802 butare not wrapped around it), etc.

Gesture detectors 324, 424 may detect the gating gesture if gesturedetectors 324, 424 identify a sequence of the gripping motion of hand132 to form gripping configuration 810 at the location corresponding tothe virtual location of assistant element 802, followed by a throwingmotion of hand 132 with respect to assistant element 802. Gesturedetectors 324, 424 may detect the throwing motion by identifying acombination of a release of gripping configuration 810, and a particularmovement of hand 132 and/or wrist 702. The particular movement mayaccompany, follow, or partially overlap with the release of grippingconfiguration 810.

FIG. 9B illustrates a throwing motion that gesture detectors 324, 424 byway of an outward flicking motion of one or more of the digits of hand132. According to throwing configuration 820 of FIG. 9B, gesturedetectors 324, 424 detect a release of gripping motion 810, in thatgesture detectors 324, 424 determine that the thumb and the otherfingers that formed gripping configuration 810 are no longer at the twopositions (e.g., the substantially diametrically opposed positions)corresponding to the virtual location of assistant element 802. In theexample of FIG. 9B, gesture detectors 324, 424 identify the subsequentthrowing motion based on outward flicking motion 804.

Gesture detectors 324, 424 may detect outward flicking motion 804 basedon a straightening of the phalanges of the thumb and the other finger(s)that formed gripping configuration 810, where the straighteningsatisfies a minimum speed so as to simulate a finger-based throw in aphysical environment. To simulate the throwing motion with respect to aUI element such as assistant element 802, UI engines 328, 428 andrendering engines 322, 422 may update artificial reality content 122 toshow movement of assistant element 802 away from hand 132, such as amovement that simulates assistant element 802.

FIG. 9C illustrates a throwing motion that gesture detectors 324, 424 byway of a flexion of wrist 702. According to throwing configuration 830of FIG. 9C, gesture detectors 324, 424 detect a release of grippingmotion 810, in that gesture detectors 324, 424 determine that the thumband the other fingers that formed gripping configuration 810 are nolonger at the two positions (e.g., the substantially diametricallyopposed positions) corresponding to the virtual location of assistantelement 802. In the example of FIG. 9C, gesture detectors 324, 424identify the subsequent throwing motion based on wrist flexion 806.

Gesture detectors 324, 424 may detect flexion 806 based on a bending ofwrist 702, along with or substantially concurrently with the release ofgripping configuration 810, if the bending of wrist 702 satisfies aminimum speed so as to simulate a wrist-based toss of assistant element802. While FIG. 9C illustrates throwing configuration 830 based on abending movement of wrist 702 to perform flexion 806, it will beappreciated that, in other use case scenarios, gesture detectors 324,424 may detect a throwing flexion based on a straightening motion ofwrist 802. To simulate the throwing motion with respect to a UI elementsuch as assistant element 802, UI engines 328, 428 and rendering engines322, 422 may update artificial reality content 122 to show an abductionmovement of assistant element 802, away from hand 132.

In various examples, in response to gesture detectors 324, 424identifying the gating gesture comprising the gripping motion to formgripping configuration 810 followed by one or both of throwing motions820, 830 UI engines 328, 428 and rendering engines 322, 422 gate a UIelement within the virtual environment represented by artificial realitycontent 122. In some examples, the UI element includes at least one menuof user-selectable options. That is, UI engines 328, 428 may generatethe UI element in response to the identification of the gesture, andrendering engines 322, 422 may render the UI element as an overlay to atleast some of artificial reality content 122.

In some use case scenarios, gesture detectors 324, 424 identifies, afterthe rendering of the UI element as the overlay to artificial realitycontent 122, a press-and-hold gesture with respect to assistant element.For instance, gesture detectors 324, 424 may detect the placement of oneof the digits of hand 132 at a location corresponding to the virtuallocation of assistant element 802, with the placement of these one ormore digits remaining in place for at least a threshold period of time.That is, gesture detectors 324, 424 may identify the press-and-holdgesture by identifying of at least one of the digits of hand 132 beingpositioned at a location that corresponds to the assistant element inthe artificial reality content and being substantially stationary for atleast a threshold period of time.

Gesture detectors 324, 424 may identify the press-and-hold gesture asoccurring after rendering engines 322, 422 render the UI element as theoverlay to artificial reality content 122. In these examples, renderingengines 322, 422 may remove the overlay of the UI element from theartificial reality content in response to gesture detectors 324, 424identifying the press-and-hold gesture at the location corresponding tothe virtual location of assistant element 802. In this way, artificialreality systems 10, 20 may de-gate the UI element (e.g., the menu) basedon input received from user 110 in the form the subsequentpress-and-hold gesture.

FIGS. 10A and 10B illustrate various configurations of hand 132 andopposite arm 934 that gesture detectors 324, 424 may use to detectgestures that generally correspond to gripping (or “holding” or“grabbing”) gestures originating from predefined areas of opposite arm934. For example, gesture detectors 324, 424 may detect thegrip-and-pull gesture if the gesture originates at opposite wrist 902 ofopposite arm 934. In the example of FIGS. 10A and 10B, UI engines 328,428 generate and render assistant element 802 to appear to passivelyreside on opposite arm 934. That is, UI engines 328, 428, and renderingengines 322, 422 may output, as part of artificial reality content 122that is displayed via electronic display 203, assistant element 802 suchthat assistant element 802 appears superimposed on and attached toopposite arm 934. For instance, UI engines 328, 428, and renderingengines 322, 422 may output assistant element 802 to appear superimposedon and attached to opposite wrist 902.

Gesture detectors 324, 424 may identify, from the image data receivedfrom image capture devices 138, a gesture that includes a grippingmotion of hand 132 with respect to assistant element 802. That is,gesture detectors 324, 424 may detect a motion of the digits of hand 132that bring the thumb and one or more other fingers together to formgripping configuration 810 of FIG. 9A, or other types of gripping (or“gripped” or “holding”) configurations. In terms of gripping assistantelement 802 in the virtual environment, the gripping motion includes thethumb of hand 132 being positioned to contact a first portion ofassistant element 802, and at least one finger (other than the thumb) ofhand 132 being positioned to contact a second portion of assistantelement 802.

For instance, the first portion of assistant element 802 may bediametrically opposed or at least approximately diametrically opposed tothe second portion of assistant element 802. Again, arm 134 is differentfrom opposite arm 934, and hand 132 is part of arm 134. Arm 134 andopposite arm 934 represent the arms of user 110 in the virtualenvironment represented by artificial reality content 122. In oneexample, arm 134 represents the dominant arm of user 110, and oppositearm 934 represents the non-dominant arm of user 110.

In the particular example of FIG. 10A, gesture detectors 324, 424identify the gesture based on identifying another motion, namely,pulling motion 908 while gripping configuration 810 is still intact.Pulling motion 908 represents an abduction moving away from oppositewrist 902. Gesture detectors 324, 424 may also identify additionalmotions while gripping configuration 810 is still intact, such as randommovements of hand 132 caused by panning and/or vertical movement and/ordepth-based translational movement of arm 134, caused by flexions ofwrist 702, etc. In these examples, so long as gripping configuration 810remains intact with respect to the two or more digits of hand 132 aroundthe virtual representation of assistant element 802, UI engines 328, 428and rendering engines 322, 422 may move assistant element 802 insynchrony with a movement of hand 132 within the virtual environmentrepresented by artificial reality content 122.

FIG. 10B illustrates a scenario in which UI engines 328, 428 andrendering engines 322, 422 gate UI menu 912 based on a placement ofassistant element 802 at a particular place within the virtualenvironment represented by artificial reality content 122. FIG. 10Billustrates an example in which UI engines 328, 428 and renderingengines 322, 422 gate UI menu 912 in response to a stoppage of pullingmotion 908 of hand 132 while gripping configuration 810 is still intact.In other examples, UI engines 328, 428 and rendering engines 322, 422may gate UI menu 912 in response to other stimuli, such as adetermination by gesture detectors 324, 424 of a release of grippingconfiguration 810, etc. UI engines 328, 428 and rendering engines 322,422 may gate various types of UI elements in response to these gesturesdetected by gesture detectors 324, 424.

UI menu 912 represents a menu of user-selectable options. UI engines328, 428 and rendering engines 322, 422 output UI menu 912 as an overlayto artificial reality content 122 to appear within the virtualenvironment. In this example, gesture detectors 324, 424 may identify asubsequent gesture performed by hand 132 that represents a menu gatinggesture. In some examples, gesture detectors 324, 424 may detect ascrolling movement that includes a translational movement of hand 132approximately in parallel with a vertical axis or vertical surface of UImenu 912. The scrolling movement may represent a scrolling gesture inwhich a checkbox included in UI menu 912 that is approximately inparallel with hand 132 (or a horizontally-extended digit thereof), andUI engines 328, 428 may update the parallel checkbox to appear in“checked” form.

FIG. 11 illustrates a grip-and-pull gesture of hand 132 originating fromopposite wrist 902 and UI elements that artificial reality systems 10,20 may invoke in response to the identification of the grip-and-pullgesture. In these examples, UI engines 328, 428 and rendering engines322, 422 may output assistant element 802 as an overlay to therepresentation of opposite wrist 902 in the virtual environmentrepresented by artificial reality content 122. Gesture detectors 324,424 may identify the grip-and-pull gesture based on detecting a grippingmotion of two or more digits of hand 132 to form gripping configuration810 at a location that corresponds to assistant element 802 in thevirtual environment, and pulling motion 918 of the two or more digits ofhand 132 away from (e.g., generally normal to) opposite wrist 902 whilein gripping configuration 810.

In response to the identification of the grip-and-pull gestureillustrated in FIG. 11, UI engines 328, 428 and rendering engines 322,422 may gate rendering of a UI element, such as circular (radial) menu922. In some examples, if pulling motion 918 terminates within apredefined distance from opposite wrist 902, UI engines 328, 428 andrendering engines 322, 422 may gate only circular menu 922. However, ifpulling motion 918 terminates at any distance from opposite wrist 902that is greater than the predefined distance, UI engines 328, 428 andrendering engines 322, 422 may provide finer granularity in terms ofuser-selectable options, by also gating rendering of granular menu 924.Granular menu 924 includes at least one additional user-selectableoption not included in the set of user-selectable options presented viacircular menu 922. In some such instances, granular menu 924 may includeone or more sub-selections that represent options that become availableafter an option from circular menu 922 has been selected. In some suchexamples, pulling motion 918 may be depicted in the artificial realitycontent as a string or line, such as in the form of virtual tether 926.The detected motion shown as pulling motion 918 may include two distinctportions, namely, a first pulling motion that terminates within thepredefined distance to gate circular menu 922, and a second pullingmotion that goes beyond the predefined distance to gate granular menu924 in addition to circular menu 922.

Upon detecting the grip-and-pull gesture, as described, and renderingcircular menu 922 and, in some examples, granular menu 924, gesturedetectors 324, 424 may further detect radial motions in a planegenerally perpendicular to motion 918 (i.e., a radial motion withrespect to an axis defined by motion 918). In response to detecting theradial motions UI engines 328, 428 renders display of assistant element802 to select and deselect UI elements within circular menu 922 and/orgranular menu 924.

Gesture detectors 324, 424 may also identify a cessation of contactbetween the thumb and the other gripping finger(s) of hand 132, therebydetecting a release of gripping configuration 810. In some suchexamples, UI engines 328, 428 and rendering engines 322, 422 may removethe overlay of circular menu 922 and (if gated) granular menu 924 inresponse to gesture detectors 324, 424 identifying the release ofgripping configuration 810. In this way, the techniques of thisdisclosure described with respect to FIG. 11 simulate a drawer or filingcabinet in terms of invoking UI elements, with an added elastic ormagnetic simulation in that the virtual drawer is “closed” upon therelease of a hand grip.

The techniques described in this disclosure may be implemented, at leastin part, in hardware, software, firmware or any combination thereof. Forexample, various aspects of the described techniques may be implementedwithin one or more processors, including one or more microprocessors,DSPs, application specific integrated circuits (ASICs), fieldprogrammable gate arrays (FPGAs), or any other equivalent integrated ordiscrete logic circuitry, as well as any combinations of suchcomponents. The term “processor” or “processing circuitry” may generallyrefer to any of the foregoing logic circuitry, fixed function circuitry,programmable circuitry, whether alone or in combination with other logiccircuitry, or any other equivalent circuitry. A control unit comprisinghardware may also perform one or more of the techniques of thisdisclosure.

Such hardware, software, and firmware may be implemented within the samedevice or within separate devices to support the various operations andfunctions described in this disclosure. In addition, any of thedescribed units, modules or components may be implemented together orseparately as discrete but interoperable logic devices. Depiction ofdifferent features as modules or units is intended to highlightdifferent functional aspects and does not necessarily imply that suchmodules or units must be realized by separate hardware or softwarecomponents. Rather, functionality associated with one or more modules orunits may be performed by separate hardware or software components orintegrated within common or separate hardware or software components.

The techniques described in this disclosure may also be embodied orencoded in a computer-readable medium, such as a computer-readablestorage medium, containing instructions. Instructions embedded orencoded in a computer-readable storage medium may cause a programmableprocessor, or other processor, to perform the method, e.g., when theinstructions are executed. Computer readable storage media may includerandom access memory (RAM), read only memory (ROM), programmable readonly memory (PROM), erasable programmable read only memory (EPROM),electronically erasable programmable read only memory (EEPROM), flashmemory, a hard disk, a CD-ROM, a floppy disk, a cassette, magneticmedia, optical media, or other computer readable media.

As described by way of various examples herein, the techniques of thedisclosure may include or be implemented in conjunction with anartificial reality system. As described, artificial reality is a form ofreality that has been adjusted in some manner before presentation to auser, which may include, e.g., a virtual reality (VR), an augmentedreality (AR), a mixed reality (MR), a hybrid reality, or somecombination and/or derivatives thereof. Artificial reality content mayinclude completely generated content or generated content combined withcaptured content (e.g., real-world photographs). The artificial realitycontent may include video, audio, haptic feedback, or some combinationthereof, and any of which may be presented in a single channel or inmultiple channels (such as stereo video that produces athree-dimensional effect to the viewer). Additionally, in someembodiments, artificial reality may be associated with applications,products, accessories, services, or some combination thereof, that are,e.g., used to create content in an artificial reality and/or used in(e.g., perform activities in) an artificial reality. The artificialreality system that provides the artificial reality content may beimplemented on various platforms, including a head-mounted display (HMD)connected to a host computer system, a standalone HMD, a mobile deviceor computing system, or any other hardware platform capable of providingartificial reality content to one or more viewers.

What is claimed is:
 1. An artificial reality system comprising: an image capture device configured to capture image data representative of a physical environment; a head-mounted display (HMD) configured to output artificial reality content; a gesture detector configured to identify, from the image data, a gesture comprising a configuration of a hand that is substantially stationary for at least a threshold period of time and positioned such that a thumb of the hand and at least one other finger of the hand form an approximate circle or an approximate circular segment; a user interface (UI) engine configured to generate a reproduction of a portion of the image data in response to the identified gesture, the portion of the image data being representative of a portion of the physical environment captured by the image capture device; and a rendering engine configured to render the reproduction of the portion of the image data representative of the portion of the physical environment captured by the HMD within a boundary defined by an inner ring formed by the approximate circle or approximate circular segment while maintaining display of a remainder of the artificial reality content.
 2. The artificial reality system of claim 1, wherein to identify the gesture, the gesture detector is configured to determine that the hand is positioned such that a normal from an area within the approximate circle or approximate circular segment is facing the HMD.
 3. The artificial reality system of claim 1, wherein the artificial reality content comprises a virtual reality environment and wherein the rendering engine renders the reproduction of the portion of the image data representative of the portion of the physical environment captured by the HMD as an overlay to the virtual reality environment.
 4. The artificial reality system of claim 1, wherein the reproduction of the portion of the image data corresponds to a portion of the physical environment that lies along the normal from the area within the circle or the circular segment facing the HMD.
 5. The artificial reality system of claim 1, wherein the UI engine is further configured to generate a UI element comprising video data, and wherein the rendering engine is further configured to display the UI element within the boundary defined by the inner ring formed by the approximate circle or approximate circular segment and as an overlay to the artificial reality content.
 6. The artificial reality system of claim 5, wherein the video data comprises a plurality of moving pictures.
 7. The artificial reality system of claim 1, wherein to detect the gesture, the gesture detector is further configured to identify the gesture as corresponding to an entry in a gesture library.
 8. The artificial reality system of claim 7, wherein the entry is included in one or more entries of the gesture library, each of the one or more entries corresponding to a predetermined gesture.
 9. The artificial reality system of claim 1, wherein the image capture device is integrated within the HMD.
 10. A non-transitory computer-readable storage medium encoded with instructions that, when executed, cause processing circuitry of an artificial reality system to: receive, from an image capture device, image data representative of a physical environment; output, via a head-mounted display (HMD), artificial reality content; identify, from the image data, a gesture comprising a configuration of a hand that is substantially stationary for at least a threshold period of time and positioned such that a thumb of the hand and at least one other finger of the hand form an approximate circle or an approximate circular segment; generate a reproduction of a portion of the image data in response to the identified gesture, the portion of the image data being representative of a portion of the physical environment captured by the image capture device; and render the portion of the image data representative of the portion of the physical environment captured by the HMD within a boundary defined by an inner ring formed by the approximate circle or approximate circular segment while maintaining display of a remainder of the artificial reality content.
 11. The artificial reality system of claim 1, wherein the portion of the image data corresponding to the portion of the physical environment that lies along the normal represents a passthrough reproduction of the portion of the physical environment that lies along the normal with respect to the artificial reality content output by the HMD.
 12. The artificial reality system of claim 1, wherein the rendering engine is further configured to render a visual representation of the hand positioned such that the thumb and the at least one other finger form the approximate circle or approximate circular segment.
 13. A method comprising: capturing, by an image capture device, image data representative of a physical environment; outputting, by a head-mounted display (HMD), artificial reality content; identifying, by a gesture detector, from the image data, a gesture comprising a configuration of a hand that is substantially stationary for at least a threshold period of time and positioned such that a thumb of the hand and at least one other finger of the hand form an approximate circle or an approximate circular segment; generating, by a user interface (UI) engine, in response to identifying of the gesture, a reproduction of a portion of the image data, the portion of the image data representative of a portion of the physical environment captured by the HMD; and rendering, by a rendering engine, the reproduction of the portion of the image data representative of the portion of the physical environment captured by the HMD within a boundary formed by an inner ring defined by the approximate circle or approximate circular segment while maintaining display of a remainder of the artificial reality content.
 14. The method of claim 13, wherein identifying the gesture comprises determining, by the gesture detector, that the hand is positioned such that a normal from an area within the approximate circle or the approximate circular segment is facing the HMD.
 15. The method of claim 13, wherein the artificial reality content comprises a virtual reality environment and wherein rendering the reproduction of a portion of the image data representative of the portion of the physical environment comprises rendering the reproduction of the portion of the image data representative of the physical environment as an overlay to the virtual reality environment.
 16. The method of claim 15, wherein the portion of the image data corresponds to a portion of the physical environment that lies along the normal from the area within the circle or the circular segment facing the HMD.
 17. The method of claim 13, wherein the method further comprises rendering video data to be displayed within the boundary defined by the inner ring formed by the approximate circle or approximate circular segment and as an overlay to the artificial reality content.
 18. The method of claim 13, wherein identifying the gesture comprises identifying, by the gesture detector, the gesture as corresponding to an entry in a gesture library.
 19. The method of claim 18, wherein the entry is included in one or more entries of the gesture library, each of the one or more entries corresponding to a predetermined gesture. 